bevy/crates/bevy_pbr/src/render/pbr_lighting.wgsl

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#define_import_path bevy_pbr::lighting
update shader imports (#10180) # Objective - bump naga_oil to 0.10 - update shader imports to use rusty syntax ## Migration Guide naga_oil 0.10 reworks the import mechanism to support more syntax to make it more rusty, and test for item use before importing to determine which imports are modules and which are items, which allows: - use rust-style imports ``` #import bevy_pbr::{ pbr_functions::{alpha_discard as discard, apply_pbr_lighting}, mesh_bindings, } ``` - import partial paths: ``` #import part::of::path ... path::remainder::function(); ``` which will call to `part::of::path::remainder::function` - use fully qualified paths without importing: ``` // #import bevy_pbr::pbr_functions bevy_pbr::pbr_functions::pbr() ``` - use imported items without qualifying ``` #import bevy_pbr::pbr_functions::pbr // for backwards compatibility the old style is still supported: // #import bevy_pbr::pbr_functions pbr ... pbr() ``` - allows most imported items to end with `_` and numbers (naga_oil#30). still doesn't allow struct members to end with `_` or numbers but it's progress. - the vast majority of existing shader code will work without changes, but will emit "deprecated" warnings for old-style imports. these can be suppressed with the `allow-deprecated` feature. - partly breaks overrides (as far as i'm aware nobody uses these yet) - now overrides will only be applied if the overriding module is added as an additional import in the arguments to `Composer::make_naga_module` or `Composer::add_composable_module`. this is necessary to support determining whether imports are modules or items.
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#import bevy_pbr::{
mesh_view_types::POINT_LIGHT_FLAGS_SPOT_LIGHT_Y_NEGATIVE,
mesh_view_bindings as view_bindings,
}
#import bevy_render::maths::PI
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
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const LAYER_BASE: u32 = 0;
const LAYER_CLEARCOAT: u32 = 1;
// From the Filament design doc
// https://google.github.io/filament/Filament.html#table_symbols
// Symbol Definition
// v View unit vector
// l Incident light unit vector
// n Surface normal unit vector
// h Half unit vector between l and v
// f BRDF
// f_d Diffuse component of a BRDF
// f_r Specular component of a BRDF
// α Roughness, remapped from using input perceptualRoughness
// σ Diffuse reflectance
// Ω Spherical domain
// f0 Reflectance at normal incidence
// f90 Reflectance at grazing angle
// χ+(a) Heaviside function (1 if a>0 and 0 otherwise)
// nior Index of refraction (IOR) of an interface
// ⟨n⋅l⟩ Dot product clamped to [0..1]
// ⟨a⟩ Saturated value (clamped to [0..1])
// The Bidirectional Reflectance Distribution Function (BRDF) describes the surface response of a standard material
// and consists of two components, the diffuse component (f_d) and the specular component (f_r):
// f(v,l) = f_d(v,l) + f_r(v,l)
//
// The form of the microfacet model is the same for diffuse and specular
// f_r(v,l) = f_d(v,l) = 1 / { |n⋅v||n⋅l| } ∫_Ω D(m,α) G(v,l,m) f_m(v,l,m) (v⋅m) (l⋅m) dm
//
// In which:
// D, also called the Normal Distribution Function (NDF) models the distribution of the microfacets
// G models the visibility (or occlusion or shadow-masking) of the microfacets
// f_m is the microfacet BRDF and differs between specular and diffuse components
//
// The above integration needs to be approximated.
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
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// Input to a lighting function for a single layer (either the base layer or the
// clearcoat layer).
struct LayerLightingInput {
// The normal vector.
N: vec3<f32>,
// The reflected vector.
R: vec3<f32>,
// The normal vector ⋅ the view vector.
NdotV: f32,
// The perceptual roughness of the layer.
perceptual_roughness: f32,
// The roughness of the layer.
roughness: f32,
}
// Input to a lighting function (`point_light`, `spot_light`,
// `directional_light`).
struct LightingInput {
#ifdef STANDARD_MATERIAL_CLEARCOAT
layers: array<LayerLightingInput, 2>,
#else // STANDARD_MATERIAL_CLEARCOAT
layers: array<LayerLightingInput, 1>,
#endif // STANDARD_MATERIAL_CLEARCOAT
// The world-space position.
P: vec3<f32>,
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
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// The vector to the view.
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
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V: vec3<f32>,
// The diffuse color of the material.
diffuse_color: vec3<f32>,
// Specular reflectance at the normal incidence angle.
//
// This should be read F₀, but due to Naga limitations we can't name it that.
F0_: vec3<f32>,
// Constants for the BRDF approximation.
//
// See `EnvBRDFApprox` in
// <https://www.unrealengine.com/en-US/blog/physically-based-shading-on-mobile>.
// What we call `F_ab` they call `AB`.
F_ab: vec2<f32>,
#ifdef STANDARD_MATERIAL_CLEARCOAT
// The strength of the clearcoat layer.
clearcoat_strength: f32,
#endif // STANDARD_MATERIAL_CLEARCOAT
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
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#ifdef STANDARD_MATERIAL_ANISOTROPY
// The anisotropy strength, reflecting the amount of increased roughness in
// the tangent direction.
anisotropy: f32,
// The tangent direction for anisotropy: i.e. the direction in which
// roughness increases.
Ta: vec3<f32>,
// The bitangent direction, which is the cross product of the normal with
// the tangent direction.
Ba: vec3<f32>,
#endif // STANDARD_MATERIAL_ANISOTROPY
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
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}
// Values derived from the `LightingInput` for both diffuse and specular lights.
struct DerivedLightingInput {
// The half-vector between L, the incident light vector, and V, the view
// vector.
H: vec3<f32>,
// The normal vector ⋅ the incident light vector.
NdotL: f32,
// The normal vector ⋅ the half-vector.
NdotH: f32,
// The incident light vector ⋅ the half-vector.
LdotH: f32,
}
// distanceAttenuation is simply the square falloff of light intensity
// combined with a smooth attenuation at the edge of the light radius
//
// light radius is a non-physical construct for efficiency purposes,
// because otherwise every light affects every fragment in the scene
fn getDistanceAttenuation(distanceSquare: f32, inverseRangeSquared: f32) -> f32 {
let factor = distanceSquare * inverseRangeSquared;
let smoothFactor = saturate(1.0 - factor * factor);
let attenuation = smoothFactor * smoothFactor;
return attenuation * 1.0 / max(distanceSquare, 0.0001);
}
// Normal distribution function (specular D)
// Based on https://google.github.io/filament/Filament.html#citation-walter07
// D_GGX(h,α) = α^2 / { π ((n⋅h)^2 (α21) + 1)^2 }
// Simple implementation, has precision problems when using fp16 instead of fp32
// see https://google.github.io/filament/Filament.html#listing_speculardfp16
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
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fn D_GGX(roughness: f32, NdotH: f32, h: vec3<f32>) -> f32 {
let oneMinusNdotHSquared = 1.0 - NdotH * NdotH;
let a = NdotH * roughness;
let k = roughness / (oneMinusNdotHSquared + a * a);
let d = k * k * (1.0 / PI);
return d;
}
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
// An approximation of the anisotropic GGX distribution function.
//
// 1
// D(𝐡) = ───────────────────────────────────────────────────
// παα_b((𝐡𝐭)² / αₜ²) + (𝐡𝐛)² / α_b² + (𝐡𝐧)²)²
//
// * `T` = 𝐭 = the tangent direction = the direction of increased roughness.
//
// * `B` = 𝐛 = the bitangent direction = the direction of decreased roughness.
//
// * `at` = αₜ = the alpha-roughness in the tangent direction.
//
// * `ab` = α_b = the alpha-roughness in the bitangent direction.
//
// This is from the `KHR_materials_anisotropy` spec:
// <https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md#individual-lights>
fn D_GGX_anisotropic(at: f32, ab: f32, NdotH: f32, TdotH: f32, BdotH: f32) -> f32 {
let a2 = at * ab;
let f = vec3(ab * TdotH, at * BdotH, a2 * NdotH);
let w2 = a2 / dot(f, f);
let d = a2 * w2 * w2 * (1.0 / PI);
return d;
}
// Visibility function (Specular G)
// V(v,l,a) = G(v,l,α) / { 4 (n⋅v) (n⋅l) }
// such that f_r becomes
// f_r(v,l) = D(h,α) V(v,l,α) F(v,h,f0)
// where
// V(v,l,α) = 0.5 / { n⋅l sqrt((n⋅v)^2 (1α2) + α2) + n⋅v sqrt((n⋅l)^2 (1α2) + α2) }
// Note the two sqrt's, that may be slow on mobile, see https://google.github.io/filament/Filament.html#listing_approximatedspecularv
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn V_SmithGGXCorrelated(roughness: f32, NdotV: f32, NdotL: f32) -> f32 {
let a2 = roughness * roughness;
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let lambdaV = NdotL * sqrt((NdotV - a2 * NdotV) * NdotV + a2);
let lambdaL = NdotV * sqrt((NdotL - a2 * NdotL) * NdotL + a2);
let v = 0.5 / (lambdaV + lambdaL);
return v;
}
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
// The visibility function, anisotropic variant.
fn V_GGX_anisotropic(
at: f32,
ab: f32,
NdotL: f32,
NdotV: f32,
BdotV: f32,
TdotV: f32,
TdotL: f32,
BdotL: f32,
) -> f32 {
let GGX_V = NdotL * length(vec3(at * TdotV, ab * BdotV, NdotV));
let GGX_L = NdotV * length(vec3(at * TdotL, ab * BdotL, NdotL));
let v = 0.5 / (GGX_V + GGX_L);
return saturate(v);
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// A simpler, but nonphysical, alternative to Smith-GGX. We use this for
// clearcoat, per the Filament spec.
//
// https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel#toc4.9.1
fn V_Kelemen(LdotH: f32) -> f32 {
return 0.25 / (LdotH * LdotH);
}
// Fresnel function
// see https://google.github.io/filament/Filament.html#citation-schlick94
// F_Schlick(v,h,f_0,f_90) = f_0 + (f_90 f_0) (1 v⋅h)^5
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn F_Schlick_vec(f0: vec3<f32>, f90: f32, VdotH: f32) -> vec3<f32> {
// not using mix to keep the vec3 and float versions identical
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
return f0 + (f90 - f0) * pow(1.0 - VdotH, 5.0);
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn F_Schlick(f0: f32, f90: f32, VdotH: f32) -> f32 {
// not using mix to keep the vec3 and float versions identical
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
return f0 + (f90 - f0) * pow(1.0 - VdotH, 5.0);
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn fresnel(f0: vec3<f32>, LdotH: f32) -> vec3<f32> {
// f_90 suitable for ambient occlusion
// see https://google.github.io/filament/Filament.html#lighting/occlusion
let f90 = saturate(dot(f0, vec3<f32>(50.0 * 0.33)));
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
return F_Schlick_vec(f0, f90, LdotH);
}
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
// Given distribution, visibility, and Fresnel term, calculates the final
// specular light.
//
// Multiscattering approximation:
// <https://google.github.io/filament/Filament.html#listing_energycompensationimpl>
fn specular_multiscatter(
input: ptr<function, LightingInput>,
D: f32,
V: f32,
F: vec3<f32>,
specular_intensity: f32,
) -> vec3<f32> {
// Unpack.
let F0 = (*input).F0_;
let F_ab = (*input).F_ab;
var Fr = (specular_intensity * D * V) * F;
Fr *= 1.0 + F0 * (1.0 / F_ab.x - 1.0);
return Fr;
}
// Specular BRDF
// https://google.github.io/filament/Filament.html#materialsystem/specularbrdf
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// N, V, and L must all be normalized.
fn derive_lighting_input(N: vec3<f32>, V: vec3<f32>, L: vec3<f32>) -> DerivedLightingInput {
var input: DerivedLightingInput;
var H: vec3<f32> = normalize(L + V);
input.H = H;
input.NdotL = saturate(dot(N, L));
input.NdotH = saturate(dot(N, H));
input.LdotH = saturate(dot(L, H));
return input;
}
// Returns L in the `xyz` components and the specular intensity in the `w` component.
fn compute_specular_layer_values_for_point_light(
input: ptr<function, LightingInput>,
layer: u32,
V: vec3<f32>,
light_to_frag: vec3<f32>,
light_position_radius: f32,
) -> vec4<f32> {
// Unpack.
let R = (*input).layers[layer].R;
let a = (*input).layers[layer].roughness;
// Representative Point Area Lights.
// see http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf p14-16
let centerToRay = dot(light_to_frag, R) * R - light_to_frag;
let closestPoint = light_to_frag + centerToRay * saturate(
light_position_radius * inverseSqrt(dot(centerToRay, centerToRay)));
let LspecLengthInverse = inverseSqrt(dot(closestPoint, closestPoint));
let normalizationFactor = a / saturate(a + (light_position_radius * 0.5 * LspecLengthInverse));
let intensity = normalizationFactor * normalizationFactor;
let L: vec3<f32> = closestPoint * LspecLengthInverse; // normalize() equivalent?
return vec4(L, intensity);
}
// Cook-Torrance approximation of the microfacet model integration using Fresnel law F to model f_m
// f_r(v,l) = { D(h,α) G(v,l,α) F(v,h,f0) } / { 4 (n⋅v) (n⋅l) }
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
fn specular(
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
input: ptr<function, LightingInput>,
derived_input: ptr<function, DerivedLightingInput>,
specular_intensity: f32,
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
) -> vec3<f32> {
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// Unpack.
let roughness = (*input).layers[LAYER_BASE].roughness;
let NdotV = (*input).layers[LAYER_BASE].NdotV;
let F0 = (*input).F0_;
let H = (*derived_input).H;
let NdotL = (*derived_input).NdotL;
let NdotH = (*derived_input).NdotH;
let LdotH = (*derived_input).LdotH;
// Calculate distribution.
let D = D_GGX(roughness, NdotH, H);
// Calculate visibility.
let V = V_SmithGGXCorrelated(roughness, NdotV, NdotL);
// Calculate the Fresnel term.
let F = fresnel(F0, LdotH);
// Calculate the specular light.
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
let Fr = specular_multiscatter(input, D, V, F, specular_intensity);
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
return Fr;
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// Calculates the specular light for the clearcoat layer. Returns Fc, the
// Fresnel term, in the first channel, and Frc, the specular clearcoat light, in
// the second channel.
//
// <https://google.github.io/filament/Filament.html#listing_clearcoatbrdf>
fn specular_clearcoat(
input: ptr<function, LightingInput>,
derived_input: ptr<function, DerivedLightingInput>,
clearcoat_strength: f32,
specular_intensity: f32,
) -> vec2<f32> {
// Unpack.
let roughness = (*input).layers[LAYER_CLEARCOAT].roughness;
let H = (*derived_input).H;
let NdotH = (*derived_input).NdotH;
let LdotH = (*derived_input).LdotH;
// Calculate distribution.
let Dc = D_GGX(roughness, NdotH, H);
// Calculate visibility.
let Vc = V_Kelemen(LdotH);
// Calculate the Fresnel term.
let Fc = F_Schlick(0.04, 1.0, LdotH) * clearcoat_strength;
// Calculate the specular light.
let Frc = (specular_intensity * Dc * Vc) * Fc;
return vec2(Fc, Frc);
}
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
#ifdef STANDARD_MATERIAL_ANISOTROPY
fn specular_anisotropy(
input: ptr<function, LightingInput>,
derived_input: ptr<function, DerivedLightingInput>,
L: vec3<f32>,
specular_intensity: f32,
) -> vec3<f32> {
// Unpack.
let roughness = (*input).layers[LAYER_BASE].roughness;
let NdotV = (*input).layers[LAYER_BASE].NdotV;
let V = (*input).V;
let F0 = (*input).F0_;
let anisotropy = (*input).anisotropy;
let Ta = (*input).Ta;
let Ba = (*input).Ba;
let H = (*derived_input).H;
let NdotL = (*derived_input).NdotL;
let NdotH = (*derived_input).NdotH;
let LdotH = (*derived_input).LdotH;
let TdotL = dot(Ta, L);
let BdotL = dot(Ba, L);
let TdotH = dot(Ta, H);
let BdotH = dot(Ba, H);
let TdotV = dot(Ta, V);
let BdotV = dot(Ba, V);
let ab = roughness * roughness;
let at = mix(ab, 1.0, anisotropy * anisotropy);
let Da = D_GGX_anisotropic(at, ab, NdotH, TdotH, BdotH);
let Va = V_GGX_anisotropic(at, ab, NdotL, NdotV, BdotV, TdotV, TdotL, BdotL);
let Fa = fresnel(F0, LdotH);
// Calculate the specular light.
let Fr = specular_multiscatter(input, Da, Va, Fa, specular_intensity);
return Fr;
}
#endif // STANDARD_MATERIAL_ANISOTROPY
// Diffuse BRDF
// https://google.github.io/filament/Filament.html#materialsystem/diffusebrdf
// fd(v,l) = σ/π * 1 / { |n⋅v||n⋅l| } ∫Ω D(m,α) G(v,l,m) (v⋅m) (l⋅m) dm
//
// simplest approximation
// float Fd_Lambert() {
// return 1.0 / PI;
// }
//
// vec3 Fd = diffuseColor * Fd_Lambert();
//
// Disney approximation
// See https://google.github.io/filament/Filament.html#citation-burley12
// minimal quality difference
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn Fd_Burley(
input: ptr<function, LightingInput>,
derived_input: ptr<function, DerivedLightingInput>,
) -> f32 {
// Unpack.
let roughness = (*input).layers[LAYER_BASE].roughness;
let NdotV = (*input).layers[LAYER_BASE].NdotV;
let NdotL = (*derived_input).NdotL;
let LdotH = (*derived_input).LdotH;
let f90 = 0.5 + 2.0 * roughness * LdotH * LdotH;
let lightScatter = F_Schlick(1.0, f90, NdotL);
let viewScatter = F_Schlick(1.0, f90, NdotV);
return lightScatter * viewScatter * (1.0 / PI);
}
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
// Scale/bias approximation
// https://www.unrealengine.com/en-US/blog/physically-based-shading-on-mobile
// TODO: Use a LUT (more accurate)
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn F_AB(perceptual_roughness: f32, NdotV: f32) -> vec2<f32> {
let c0 = vec4<f32>(-1.0, -0.0275, -0.572, 0.022);
let c1 = vec4<f32>(1.0, 0.0425, 1.04, -0.04);
let r = perceptual_roughness * c0 + c1;
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let a004 = min(r.x * r.x, exp2(-9.28 * NdotV)) * r.x + r.y;
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
return vec2<f32>(-1.04, 1.04) * a004 + r.zw;
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn EnvBRDFApprox(F0: vec3<f32>, F_ab: vec2<f32>) -> vec3<f32> {
return F0 * F_ab.x + F_ab.y;
}
fn perceptualRoughnessToRoughness(perceptualRoughness: f32) -> f32 {
// clamp perceptual roughness to prevent precision problems
// According to Filament design 0.089 is recommended for mobile
// Filament uses 0.045 for non-mobile
let clampedPerceptualRoughness = clamp(perceptualRoughness, 0.089, 1.0);
return clampedPerceptualRoughness * clampedPerceptualRoughness;
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn point_light(light_id: u32, input: ptr<function, LightingInput>) -> vec3<f32> {
// Unpack.
let diffuse_color = (*input).diffuse_color;
let P = (*input).P;
let N = (*input).layers[LAYER_BASE].N;
let V = (*input).V;
let light = &view_bindings::clusterable_objects.data[light_id];
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let light_to_frag = (*light).position_radius.xyz - P;
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
let L = normalize(light_to_frag);
let distance_square = dot(light_to_frag, light_to_frag);
EnvironmentMapLight, BRDF Improvements (#7051) (Before) ![image](https://user-images.githubusercontent.com/47158642/213946111-15ec758f-1f1d-443c-b196-1fdcd4ae49da.png) (After) ![image](https://user-images.githubusercontent.com/47158642/217051179-67381e73-dd44-461b-a2c7-87b0440ef8de.png) ![image](https://user-images.githubusercontent.com/47158642/212492404-524e4ad3-7837-4ed4-8b20-2abc276aa8e8.png) # Objective - Improve lighting; especially reflections. - Closes https://github.com/bevyengine/bevy/issues/4581. ## Solution - Implement environment maps, providing better ambient light. - Add microfacet multibounce approximation for specular highlights from Filament. - Occlusion is no longer incorrectly applied to direct lighting. It now only applies to diffuse indirect light. Unsure if it's also supposed to apply to specular indirect light - the glTF specification just says "indirect light". In the case of ambient occlusion, for instance, that's usually only calculated as diffuse though. For now, I'm choosing to apply this just to indirect diffuse light, and not specular. - Modified the PBR example to use an environment map, and have labels. - Added `FallbackImageCubemap`. ## Implementation - IBL technique references can be found in environment_map.wgsl. - It's more accurate to use a LUT for the scale/bias. Filament has a good reference on generating this LUT. For now, I just used an analytic approximation. - For now, environment maps must first be prefiltered outside of bevy using a 3rd party tool. See the `EnvironmentMap` documentation. - Eventually, we should have our own prefiltering code, so that we can have dynamically changing environment maps, as well as let users drop in an HDR image and use asset preprocessing to create the needed textures using only bevy. --- ## Changelog - Added an `EnvironmentMapLight` camera component that adds additional ambient light to a scene. - StandardMaterials will now appear brighter and more saturated at high roughness, due to internal material changes. This is more physically correct. - Fixed StandardMaterial occlusion being incorrectly applied to direct lighting. - Added `FallbackImageCubemap`. Co-authored-by: IceSentry <c.giguere42@gmail.com> Co-authored-by: James Liu <contact@jamessliu.com> Co-authored-by: Rob Parrett <robparrett@gmail.com>
2023-02-09 16:46:32 +00:00
let rangeAttenuation = getDistanceAttenuation(distance_square, (*light).color_inverse_square_range.w);
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// Base layer
let specular_L_intensity = compute_specular_layer_values_for_point_light(
input,
LAYER_BASE,
V,
light_to_frag,
(*light).position_radius.w,
);
var specular_derived_input = derive_lighting_input(N, V, specular_L_intensity.xyz);
let specular_intensity = specular_L_intensity.w;
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
#ifdef STANDARD_MATERIAL_ANISOTROPY
let specular_light = specular_anisotropy(input, &specular_derived_input, L, specular_intensity);
#else // STANDARD_MATERIAL_ANISOTROPY
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let specular_light = specular(input, &specular_derived_input, specular_intensity);
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
#endif // STANDARD_MATERIAL_ANISOTROPY
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// Clearcoat
#ifdef STANDARD_MATERIAL_CLEARCOAT
// Unpack.
let clearcoat_N = (*input).layers[LAYER_CLEARCOAT].N;
let clearcoat_strength = (*input).clearcoat_strength;
// Perform specular input calculations again for the clearcoat layer. We
// can't reuse the above because the clearcoat normal might be different
// from the main layer normal.
let clearcoat_specular_L_intensity = compute_specular_layer_values_for_point_light(
input,
LAYER_CLEARCOAT,
V,
light_to_frag,
(*light).position_radius.w,
);
var clearcoat_specular_derived_input =
derive_lighting_input(clearcoat_N, V, clearcoat_specular_L_intensity.xyz);
// Calculate the specular light.
let clearcoat_specular_intensity = clearcoat_specular_L_intensity.w;
let Fc_Frc = specular_clearcoat(
input,
&clearcoat_specular_derived_input,
clearcoat_strength,
clearcoat_specular_intensity
);
let inv_Fc = 1.0 - Fc_Frc.r; // Inverse Fresnel term.
let Frc = Fc_Frc.g; // Clearcoat light.
#endif // STANDARD_MATERIAL_CLEARCOAT
// Diffuse.
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
// Comes after specular since its N⋅L is used in the lighting equation.
var derived_input = derive_lighting_input(N, V, L);
let diffuse = diffuse_color * Fd_Burley(input, &derived_input);
// See https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminanceEquation
// Lout = f(v,l) Φ / { 4 π d^2 }⟨n⋅l⟩
// where
// f(v,l) = (f_d(v,l) + f_r(v,l)) * light_color
// Φ is luminous power in lumens
// our rangeAttenuation = 1 / d^2 multiplied with an attenuation factor for smoothing at the edge of the non-physical maximum light radius
// For a point light, luminous intensity, I, in lumens per steradian is given by:
// I = Φ / 4 π
// The derivation of this can be seen here: https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminousPower
// NOTE: (*light).color.rgb is premultiplied with (*light).intensity / 4 π (which would be the luminous intensity) on the CPU
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
var color: vec3<f32>;
#ifdef STANDARD_MATERIAL_CLEARCOAT
// Account for the Fresnel term from the clearcoat darkening the main layer.
//
// <https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel/integrationinthesurfaceresponse>
color = (diffuse + specular_light * inv_Fc) * inv_Fc + Frc;
#else // STANDARD_MATERIAL_CLEARCOAT
color = diffuse + specular_light;
#endif // STANDARD_MATERIAL_CLEARCOAT
return color * (*light).color_inverse_square_range.rgb *
(rangeAttenuation * derived_input.NdotL);
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn spot_light(light_id: u32, input: ptr<function, LightingInput>) -> vec3<f32> {
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
// reuse the point light calculations
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let point_light = point_light(light_id, input);
let light = &view_bindings::clusterable_objects.data[light_id];
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
// reconstruct spot dir from x/z and y-direction flag
var spot_dir = vec3<f32>((*light).light_custom_data.x, 0.0, (*light).light_custom_data.y);
spot_dir.y = sqrt(max(0.0, 1.0 - spot_dir.x * spot_dir.x - spot_dir.z * spot_dir.z));
update shader imports (#10180) # Objective - bump naga_oil to 0.10 - update shader imports to use rusty syntax ## Migration Guide naga_oil 0.10 reworks the import mechanism to support more syntax to make it more rusty, and test for item use before importing to determine which imports are modules and which are items, which allows: - use rust-style imports ``` #import bevy_pbr::{ pbr_functions::{alpha_discard as discard, apply_pbr_lighting}, mesh_bindings, } ``` - import partial paths: ``` #import part::of::path ... path::remainder::function(); ``` which will call to `part::of::path::remainder::function` - use fully qualified paths without importing: ``` // #import bevy_pbr::pbr_functions bevy_pbr::pbr_functions::pbr() ``` - use imported items without qualifying ``` #import bevy_pbr::pbr_functions::pbr // for backwards compatibility the old style is still supported: // #import bevy_pbr::pbr_functions pbr ... pbr() ``` - allows most imported items to end with `_` and numbers (naga_oil#30). still doesn't allow struct members to end with `_` or numbers but it's progress. - the vast majority of existing shader code will work without changes, but will emit "deprecated" warnings for old-style imports. these can be suppressed with the `allow-deprecated` feature. - partly breaks overrides (as far as i'm aware nobody uses these yet) - now overrides will only be applied if the overriding module is added as an additional import in the arguments to `Composer::make_naga_module` or `Composer::add_composable_module`. this is necessary to support determining whether imports are modules or items.
2023-10-21 11:51:58 +00:00
if ((*light).flags & POINT_LIGHT_FLAGS_SPOT_LIGHT_Y_NEGATIVE) != 0u {
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
spot_dir.y = -spot_dir.y;
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let light_to_frag = (*light).position_radius.xyz - (*input).P.xyz;
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
// calculate attenuation based on filament formula https://google.github.io/filament/Filament.html#listing_glslpunctuallight
// spot_scale and spot_offset have been precomputed
// note we normalize here to get "l" from the filament listing. spot_dir is already normalized
let cd = dot(-spot_dir, normalize(light_to_frag));
let attenuation = saturate(cd * (*light).light_custom_data.z + (*light).light_custom_data.w);
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
let spot_attenuation = attenuation * attenuation;
return point_light * spot_attenuation;
Spotlights (#4715) # Objective add spotlight support ## Solution / Changelog - add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation. - add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl`` - reduce no-buffer-support max point light count to 204 due to above - use spotlight data to attenuate light in ``pbr.wgsl`` - do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters`` - changed one of the lights in the lighting demo to a spotlight - also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily ## notes increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps. i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small. the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light. Co-authored-by: François <mockersf@gmail.com>
2022-07-08 19:57:43 +00:00
}
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
fn directional_light(light_id: u32, input: ptr<function, LightingInput>) -> vec3<f32> {
// Unpack.
let diffuse_color = (*input).diffuse_color;
let NdotV = (*input).layers[LAYER_BASE].NdotV;
let N = (*input).layers[LAYER_BASE].N;
let V = (*input).V;
let roughness = (*input).layers[LAYER_BASE].roughness;
improve shader import model (#5703) # Objective operate on naga IR directly to improve handling of shader modules. - give codespan reporting into imported modules - allow glsl to be used from wgsl and vice-versa the ultimate objective is to make it possible to - provide user hooks for core shader functions (to modify light behaviour within the standard pbr pipeline, for example) - make automatic binding slot allocation possible but ... since this is already big, adds some value and (i think) is at feature parity with the existing code, i wanted to push this now. ## Solution i made a crate called naga_oil (https://github.com/robtfm/naga_oil - unpublished for now, could be part of bevy) which manages modules by - building each module independantly to naga IR - creating "header" files for each supported language, which are used to build dependent modules/shaders - make final shaders by combining the shader IR with the IR for imported modules then integrated this into bevy, replacing some of the existing shader processing stuff. also reworked examples to reflect this. ## Migration Guide shaders that don't use `#import` directives should work without changes. the most notable user-facing difference is that imported functions/variables/etc need to be qualified at point of use, and there's no "leakage" of visible stuff into your shader scope from the imports of your imports, so if you used things imported by your imports, you now need to import them directly and qualify them. the current strategy of including/'spreading' `mesh_vertex_output` directly into a struct doesn't work any more, so these need to be modified as per the examples (e.g. color_material.wgsl, or many others). mesh data is assumed to be in bindgroup 2 by default, if mesh data is bound into bindgroup 1 instead then the shader def `MESH_BINDGROUP_1` needs to be added to the pipeline shader_defs.
2023-06-27 00:29:22 +00:00
let light = &view_bindings::lights.directional_lights[light_id];
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
let L = (*light).direction_to_light.xyz;
var derived_input = derive_lighting_input(N, V, L);
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let diffuse = diffuse_color * Fd_Burley(input, &derived_input);
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
#ifdef STANDARD_MATERIAL_ANISOTROPY
let specular_light = specular_anisotropy(input, &derived_input, L, 1.0);
#else // STANDARD_MATERIAL_ANISOTROPY
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let specular_light = specular(input, &derived_input, 1.0);
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
#endif // STANDARD_MATERIAL_ANISOTROPY
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
#ifdef STANDARD_MATERIAL_CLEARCOAT
let clearcoat_N = (*input).layers[LAYER_CLEARCOAT].N;
let clearcoat_strength = (*input).clearcoat_strength;
// Perform specular input calculations again for the clearcoat layer. We
// can't reuse the above because the clearcoat normal might be different
// from the main layer normal.
Implement PBR anisotropy per `KHR_materials_anisotropy`. (#13450) This commit implements support for physically-based anisotropy in Bevy's `StandardMaterial`, following the specification for the [`KHR_materials_anisotropy`] glTF extension. [*Anisotropy*] (not to be confused with [anisotropic filtering]) is a PBR feature that allows roughness to vary along the tangent and bitangent directions of a mesh. In effect, this causes the specular light to stretch out into lines instead of a round lobe. This is useful for modeling brushed metal, hair, and similar surfaces. Support for anisotropy is a common feature in major game and graphics engines; Unity, Unreal, Godot, three.js, and Blender all support it to varying degrees. Two new parameters have been added to `StandardMaterial`: `anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength, which ranges from 0 to 1, represents how much the roughness differs between the tangent and the bitangent of the mesh. In effect, it controls how stretched the specular highlight is. Anisotropy rotation allows the roughness direction to differ from the tangent of the model. In addition to these two fixed parameters, an *anisotropy texture* can be supplied. Such a texture should be a 3-channel RGB texture, where the red and green values specify a direction vector using the same conventions as a normal map ([0, 1] color values map to [-1, 1] vector values), and the the blue value represents the strength. This matches the format that the [`KHR_materials_anisotropy`] specification requires. Such textures should be loaded as linear and not sRGB. Note that this texture does consume one additional texture binding in the standard material shader. The glTF loader has been updated to properly parse the `KHR_materials_anisotropy` extension. A new example, `anisotropy`, has been added. This example loads and displays the barn lamp example from the [`glTF-Sample-Assets`] repository. Note that the textures were rather large, so I shrunk them down and converted them to a mixture of JPEG and KTX2 format, in the interests of saving space in the Bevy repository. [*Anisotropy*]: https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel [anisotropic filtering]: https://en.wikipedia.org/wiki/Anisotropic_filtering [`KHR_materials_anisotropy`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md [`glTF-Sample-Assets`]: https://github.com/KhronosGroup/glTF-Sample-Assets/ ## Changelog ### Added * Physically-based anisotropy is now available for materials, which enhances the look of surfaces such as brushed metal or hair. glTF scenes can use the new feature with the `KHR_materials_anisotropy` extension. ## Screenshots With anisotropy: ![Screenshot 2024-05-20 233414](https://github.com/bevyengine/bevy/assets/157897/379f1e42-24e9-40b6-a430-f7d1479d0335) Without anisotropy: ![Screenshot 2024-05-20 233420](https://github.com/bevyengine/bevy/assets/157897/aa220f05-b8e7-417c-9671-b242d4bf9fc4)
2024-06-03 23:46:06 +00:00
var derived_clearcoat_input = derive_lighting_input(clearcoat_N, V, L);
Implement clearcoat per the Filament and the `KHR_materials_clearcoat` specifications. (#13031) Clearcoat is a separate material layer that represents a thin translucent layer of a material. Examples include (from the [Filament spec]) car paint, soda cans, and lacquered wood. This commit implements support for clearcoat following the Filament and Khronos specifications, marking the beginnings of support for multiple PBR layers in Bevy. The [`KHR_materials_clearcoat`] specification describes the clearcoat support in glTF. In Blender, applying a clearcoat to the Principled BSDF node causes the clearcoat settings to be exported via this extension. As of this commit, Bevy parses and reads the extension data when present in glTF. Note that the `gltf` crate has no support for `KHR_materials_clearcoat`; this patch therefore implements the JSON semantics manually. Clearcoat is integrated with `StandardMaterial`, but the code is behind a series of `#ifdef`s that only activate when clearcoat is present. Additionally, the `pbr_feature_layer_material_textures` Cargo feature must be active in order to enable support for clearcoat factor maps, clearcoat roughness maps, and clearcoat normal maps. This approach mirrors the same pattern used by the existing transmission feature and exists to avoid running out of texture bindings on platforms like WebGL and WebGPU. Note that constant clearcoat factors and roughness values *are* supported in the browser; only the relatively-less-common maps are disabled on those platforms. This patch refactors the lighting code in `StandardMaterial` significantly in order to better support multiple layers in a natural way. That code was due for a refactor in any case, so this is a nice improvement. A new demo, `clearcoat`, has been added. It's based on [the corresponding three.js demo], but all the assets (aside from the skybox and environment map) are my original work. [Filament spec]: https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel [`KHR_materials_clearcoat`]: https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md [the corresponding three.js demo]: https://threejs.org/examples/webgl_materials_physical_clearcoat.html ![Screenshot 2024-04-19 101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2) ![Screenshot 2024-04-19 102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27) ## Changelog ### Added * `StandardMaterial` now supports a clearcoat layer, which represents a thin translucent layer over an underlying material. * The glTF loader now supports the `KHR_materials_clearcoat` extension, representing materials with clearcoat layers. ## Migration Guide * The lighting functions in the `pbr_lighting` WGSL module now have clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined. * The `R` reflection vector parameter has been removed from some lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
let Fc_Frc =
specular_clearcoat(input, &derived_clearcoat_input, clearcoat_strength, 1.0);
let inv_Fc = 1.0 - Fc_Frc.r;
let Frc = Fc_Frc.g;
#endif // STANDARD_MATERIAL_CLEARCOAT
var color: vec3<f32>;
#ifdef STANDARD_MATERIAL_CLEARCOAT
// Account for the Fresnel term from the clearcoat darkening the main layer.
//
// <https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel/integrationinthesurfaceresponse>
color = (diffuse + specular_light * inv_Fc) * inv_Fc * derived_input.NdotL +
Frc * derived_clearcoat_input.NdotL;
#else // STANDARD_MATERIAL_CLEARCOAT
color = (diffuse + specular_light) * derived_input.NdotL;
#endif // STANDARD_MATERIAL_CLEARCOAT
return color * (*light).color.rgb;
}