# Objective
Allow shadow mapping to be enabled/disabled per-light.
## Solution
- NOTE: This PR is on top of https://github.com/bevyengine/bevy/pull/3072
- Add `shadows_enabled` boolean property to `PointLight` and `DirectionalLight` components.
- Do not update the frusta for the light if shadows are disabled.
- Do not check for visible entities for the light if shadows are disabled.
- Do not fetch shadows for lights with shadows disabled.
- I reworked a few types for clarity: `ViewLight` -> `ShadowView`, the bulk of `ViewLights` members -> `ViewShadowBindings`, the entities Vec in `ViewLights` -> `ViewLightEntities`, the uniform offset in `ViewLights` for `GpuLights` -> `ViewLightsUniformOffset`
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
## Shader Imports
This adds "whole file" shader imports. These come in two flavors:
### Asset Path Imports
```rust
// /assets/shaders/custom.wgsl
#import "shaders/custom_material.wgsl"
[[stage(fragment)]]
fn fragment() -> [[location(0)]] vec4<f32> {
return get_color();
}
```
```rust
// /assets/shaders/custom_material.wgsl
[[block]]
struct CustomMaterial {
color: vec4<f32>;
};
[[group(1), binding(0)]]
var<uniform> material: CustomMaterial;
```
### Custom Path Imports
Enables defining custom import paths. These are intended to be used by crates to export shader functionality:
```rust
// bevy_pbr2/src/render/pbr.wgsl
#import bevy_pbr::mesh_view_bind_group
#import bevy_pbr::mesh_bind_group
[[block]]
struct StandardMaterial {
base_color: vec4<f32>;
emissive: vec4<f32>;
perceptual_roughness: f32;
metallic: f32;
reflectance: f32;
flags: u32;
};
/* rest of PBR fragment shader here */
```
```rust
impl Plugin for MeshRenderPlugin {
fn build(&self, app: &mut bevy_app::App) {
let mut shaders = app.world.get_resource_mut::<Assets<Shader>>().unwrap();
shaders.set_untracked(
MESH_BIND_GROUP_HANDLE,
Shader::from_wgsl(include_str!("mesh_bind_group.wgsl"))
.with_import_path("bevy_pbr::mesh_bind_group"),
);
shaders.set_untracked(
MESH_VIEW_BIND_GROUP_HANDLE,
Shader::from_wgsl(include_str!("mesh_view_bind_group.wgsl"))
.with_import_path("bevy_pbr::mesh_view_bind_group"),
);
```
By convention these should use rust-style module paths that start with the crate name. Ultimately we might enforce this convention.
Note that this feature implements _run time_ import resolution. Ultimately we should move the import logic into an asset preprocessor once Bevy gets support for that.
## Decouple Mesh Logic from PBR Logic via MeshRenderPlugin
This breaks out mesh rendering code from PBR material code, which improves the legibility of the code, decouples mesh logic from PBR logic, and opens the door for a future `MaterialPlugin<T: Material>` that handles all of the pipeline setup for arbitrary shader materials.
## Removed `RenderAsset<Shader>` in favor of extracting shaders into RenderPipelineCache
This simplifies the shader import implementation and removes the need to pass around `RenderAssets<Shader>`.
## RenderCommands are now fallible
This allows us to cleanly handle pipelines+shaders not being ready yet. We can abort a render command early in these cases, preventing bevy from trying to bind group / do draw calls for pipelines that couldn't be bound. This could also be used in the future for things like "components not existing on entities yet".
# Next Steps
* Investigate using Naga for "partial typed imports" (ex: `#import bevy_pbr::material::StandardMaterial`, which would import only the StandardMaterial struct)
* Implement `MaterialPlugin<T: Material>` for low-boilerplate custom material shaders
* Move shader import logic into the asset preprocessor once bevy gets support for that.
Fixes#3132
# Objective
Add depth prepass and support for opaque, alpha mask, and alpha blend modes for the 3D PBR target.
## Solution
NOTE: This is based on top of #2861 frustum culling. Just lining it up to keep @cart loaded with the review train. 🚂
There are a lot of important details here. Big thanks to @cwfitzgerald of wgpu, naga, and rend3 fame for explaining how to do it properly!
* An `AlphaMode` component is added that defines whether a material should be considered opaque, an alpha mask (with a cutoff value that defaults to 0.5, the same as glTF), or transparent and should be alpha blended
* Two depth prepasses are added:
* Opaque does a plain vertex stage
* Alpha mask does the vertex stage but also a fragment stage that samples the colour for the fragment and discards if its alpha value is below the cutoff value
* Both are sorted front to back, not that it matters for these passes. (Maybe there should be a way to skip sorting?)
* Three main passes are added:
* Opaque and alpha mask passes use a depth comparison function of Equal such that only the geometry that was closest is processed further, due to early-z testing
* The transparent pass uses the Greater depth comparison function so that only transparent objects that are closer than anything opaque are rendered
* The opaque fragment shading is as before except that alpha is explicitly set to 1.0
* Alpha mask fragment shading sets the alpha value to 1.0 if it is equal to or above the cutoff, as defined by glTF
* Opaque and alpha mask are sorted front to back (again not that it matters as we will skip anything that is not equal... maybe sorting is no longer needed here?)
* Transparent is sorted back to front. Transparent fragment shading uses the alpha blending over operator
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Support tangent vertex attributes, and normal maps
- Support loading these from glTF models
## Solution
- Make two pipelines in both the shadow and pbr passes, one for without normal maps, one for with normal maps
- Select the correct pipeline to bind based on the presence of the normal map texture
- Share the vertex attribute layout between shadow and pbr passes
- Refactored pbr.wgsl to share a bunch of common code between the normal map and non-normal map entry points. I tried to do this in a way that will allow custom shader reuse.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Upgrades both the old and new renderer to wgpu 0.11 (and naga 0.7). This builds on @zicklag's work here #2556.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
This changes how render logic is composed to make it much more modular. Previously, all extraction logic was centralized for a given "type" of rendered thing. For example, we extracted meshes into a vector of ExtractedMesh, which contained the mesh and material asset handles, the transform, etc. We looked up bindings for "drawn things" using their index in the `Vec<ExtractedMesh>`. This worked fine for built in rendering, but made it hard to reuse logic for "custom" rendering. It also prevented us from reusing things like "extracted transforms" across contexts.
To make rendering more modular, I made a number of changes:
* Entities now drive rendering:
* We extract "render components" from "app components" and store them _on_ entities. No more centralized uber lists! We now have true "ECS-driven rendering"
* To make this perform well, I implemented #2673 in upstream Bevy for fast batch insertions into specific entities. This was merged into the `pipelined-rendering` branch here: #2815
* Reworked the `Draw` abstraction:
* Generic `PhaseItems`: each draw phase can define its own type of "rendered thing", which can define its own "sort key"
* Ported the 2d, 3d, and shadow phases to the new PhaseItem impl (currently Transparent2d, Transparent3d, and Shadow PhaseItems)
* `Draw` trait and and `DrawFunctions` are now generic on PhaseItem
* Modular / Ergonomic `DrawFunctions` via `RenderCommands`
* RenderCommand is a trait that runs an ECS query and produces one or more RenderPass calls. Types implementing this trait can be composed to create a final DrawFunction. For example the DrawPbr DrawFunction is created from the following DrawCommand tuple. Const generics are used to set specific bind group locations:
```rust
pub type DrawPbr = (
SetPbrPipeline,
SetMeshViewBindGroup<0>,
SetStandardMaterialBindGroup<1>,
SetTransformBindGroup<2>,
DrawMesh,
);
```
* The new `custom_shader_pipelined` example illustrates how the commands above can be reused to create a custom draw function:
```rust
type DrawCustom = (
SetCustomMaterialPipeline,
SetMeshViewBindGroup<0>,
SetTransformBindGroup<2>,
DrawMesh,
);
```
* ExtractComponentPlugin and UniformComponentPlugin:
* Simple, standardized ways to easily extract individual components and write them to GPU buffers
* Ported PBR and Sprite rendering to the new primitives above.
* Removed staging buffer from UniformVec in favor of direct Queue usage
* Makes UniformVec much easier to use and more ergonomic. Completely removes the need for custom render graph nodes in these contexts (see the PbrNode and view Node removals and the much simpler call patterns in the relevant Prepare systems).
* Added a many_cubes_pipelined example to benchmark baseline 3d rendering performance and ensure there were no major regressions during this port. Avoiding regressions was challenging given that the old approach of extracting into centralized vectors is basically the "optimal" approach. However thanks to a various ECS optimizations and render logic rephrasing, we pretty much break even on this benchmark!
* Lifetimeless SystemParams: this will be a bit divisive, but as we continue to embrace "trait driven systems" (ex: ExtractComponentPlugin, UniformComponentPlugin, DrawCommand), the ergonomics of `(Query<'static, 'static, (&'static A, &'static B, &'static)>, Res<'static, C>)` were getting very hard to bear. As a compromise, I added "static type aliases" for the relevant SystemParams. The previous example can now be expressed like this: `(SQuery<(Read<A>, Read<B>)>, SRes<C>)`. If anyone has better ideas / conflicting opinions, please let me know!
* RunSystem trait: a way to define Systems via a trait with a SystemParam associated type. This is used to implement the various plugins mentioned above. I also added SystemParamItem and QueryItem type aliases to make "trait stye" ecs interactions nicer on the eyes (and fingers).
* RenderAsset retrying: ensures that render assets are only created when they are "ready" and allows us to create bind groups directly inside render assets (which significantly simplified the StandardMaterial code). I think ultimately we should swap this out on "asset dependency" events to wait for dependencies to load, but this will require significant asset system changes.
* Updated some built in shaders to account for missing MeshUniform fields
# Objective
Forward perspective projections have poor floating point precision distribution over the depth range. Reverse projections fair much better, and instead of having to have a far plane, with the reverse projection, using an infinite far plane is not a problem. The infinite reverse perspective projection has become the industry standard. The renderer rework is a great time to migrate to it.
## Solution
All perspective projections, including point lights, have been moved to using `glam::Mat4::perspective_infinite_reverse_rh()` and so have no far plane. As various depth textures are shared between orthographic and perspective projections, a quirk of this PR is that the near and far planes of the orthographic projection are swapped when the Mat4 is computed. This has no impact on 2D/3D orthographic projection usage, and provides consistency in shaders, texture clear values, etc. throughout the codebase.
## Known issues
For some reason, when looking along -Z, all geometry is black. The camera can be translated up/down / strafed left/right and geometry will still be black. Moving forward/backward or rotating the camera away from looking exactly along -Z causes everything to work as expected.
I have tried to debug this issue but both in macOS and Windows I get crashes when doing pixel debugging. If anyone could reproduce this and debug it I would be very grateful. Otherwise I will have to try to debug it further without pixel debugging, though the projections and such all looked fine to me.
# Objective
- Avoid unnecessary work in the vertex shader of the numerous shadow passes
- Have the natural order of bind groups in the pbr shader: view, material, mesh
## Solution
- Separate out the vertex stage of pbr.wgsl into depth.wgsl
- Remove the unnecessary calculation of uv and normal, as well as removing the unnecessary vertex inputs and outputs
- Use the depth.wgsl for shadow passes
- Reorder the bind groups in pbr.wgsl and PbrShaders to be 0 - view, 1 - material, 2 - mesh in decreasing order of rebind frequency
# Objective
Allow marking meshes as not casting / receiving shadows.
## Solution
- Added `NotShadowCaster` and `NotShadowReceiver` zero-sized type components.
- Extract these components into `bool`s in `ExtractedMesh`
- Only generate `DrawShadowMesh` `Drawable`s for meshes _without_ `NotShadowCaster`
- Add a `u32` bit `flags` member to `MeshUniform` with one flag indicating whether the mesh is a shadow receiver
- If a mesh does _not_ have the `NotShadowReceiver` component, then it is a shadow receiver, and so the bit in the `MeshUniform` is set, otherwise it is not set.
- Added an example illustrating the functionality.
NOTE: I wanted to have the default state of a mesh as being a shadow caster and shadow receiver, hence the `Not*` components. However, I am on the fence about this. I don't want to have a negative performance impact, nor have people wondering why their custom meshes don't have shadows because they forgot to add `ShadowCaster` and `ShadowReceiver` components, but I also really don't like the double negatives the `Not*` approach incurs. What do you think?
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
A question was raised on Discord about the units of the `PointLight` `intensity` member.
After digging around in the bevy_pbr2 source code and [Google Filament documentation](https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminousPower) I discovered that the intention by Filament was that the 'intensity' value for point lights would be in lumens. This makes a lot of sense as these are quite relatable units given basically all light bulbs I've seen sold over the past years are rated in lumens as people move away from thinking about how bright a bulb is relative to a non-halogen incandescent bulb.
However, it seems that the derivation of the conversion between luminous power (lumens, denoted `Φ` in the Filament formulae) and luminous intensity (lumens per steradian, `I` in the Filament formulae) was missed and I can see why as it is tucked right under equation 58 at the link above. As such, while the formula states that for a point light, `I = Φ / 4 π` we have been using `intensity` as if it were luminous intensity `I`.
Before this PR, the intensity field is luminous intensity in lumens per steradian. After this PR, the intensity field is luminous power in lumens, [as suggested by Filament](https://google.github.io/filament/Filament.html#table_lighttypesunits) (unfortunately the link jumps to the table's caption so scroll up to see the actual table).
I appreciate that it may be confusing to call this an intensity, but I think this is intended as more of a non-scientific, human-relatable general term with a bit of hand waving so that most light types can just have an intensity field and for most of them it works in the same way or at least with some relatable value. I'm inclined to think this is reasonable rather than throwing terms like luminous power, luminous intensity, blah at users.
## Solution
- Documented the `PointLight` `intensity` member as 'luminous power' in units of lumens.
- Added a table of examples relating from various types of household lighting to lumen values.
- Added in the mapping from luminous power to luminous intensity when premultiplying the intensity into the colour before it is made into a graphics uniform.
- Updated the documentation in `pbr.wgsl` to clarify the earlier confusion about the missing `/ 4 π`.
- Bumped the intensity of the point lights in `3d_scene_pipelined` to 1600 lumens.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
* 3d_scene_pipelined: Use a shallower directional light angle to provoke acne
* cornell_box_pipelined: Remove bias tweaks
* bevy_pbr2: Simplify shadow biases by moving them to linear depth
* bevy_pbr2: Do not use DepthBiasState
* bevy_pbr2: Do not use bilinear filtering for sampling depth textures
* pbr.wgsl: Remove unnecessary comment
* bevy_pbr2: Do manual shadow map depth comparisons for more flexibility
* examples: Add shadow_biases_pipelined example
This is useful for stress testing biases.
* bevy_pbr2: Scale the point light normal bias by the shadow map texel size
This allows the normal bias to be small close to the light source where the
shadow map texel to screen texel ratio is high, but is appropriately large
further away from the light source where the shadow map texel can easily cover
multiple screen texels.
* shadow_biases_pipelined: Add support for toggling directional / point light
* shadow_biases_pipelined: Cleanup
* bevy_pbr2: Scale the directional light normal bias by the shadow map texel size
* shadow_biases_pipelined: Fit the orthographic projection around the scene
* bevy_pbr2: Directional lights should have no shadows outside their projection
Before this change, sampling a fragment position from outside the ndc volume
would result in the return sample being clamped to the edge in x,y or possibly
always casting a shadow for fragment positions past the orthographic
projection's far plane.
* bevy_pbr2: Fix the default directional light normal bias
* Revert "bevy_pbr2: Do manual shadow map depth comparisons for more flexibility"
This reverts commit 7df1bab38a42d8a33bc50ca583d4be37bd9c9f0d.
* shadow_biases_pipelined: Adjust directional light normal bias in 0.1 increments
* pbr.wgsl: Add a couple of clarifying comments
* Revert "bevy_pbr2: Do not use bilinear filtering for sampling depth textures"
This reverts commit f53baab0232ce218866a45cad6902b470f4cf2c4.
* shadow_biases_pipelined: Print usage to terminal
* 3d_scene_pipelined: Use a shallower directional light angle to provoke acne
* cornell_box_pipelined: Remove bias tweaks
* bevy_pbr2: Simplify shadow biases by moving them to linear depth
