Commit graph

104 commits

Author SHA1 Message Date
Martin Lysell
594074149d
Fix screenspace_texture example shader compiler error in WebGPU (Browser) (#8682)
# Objective

Fix the screenspace_texture example not working on the WebGPU examples
page. Currently it fails with the following error in the browser
console:

```
1 error(s) generated while compiling the shader:
:213:9 error: redeclaration of 'uv'
    let uv = coords_to_viewport_uv(position.xy, view.viewport);
        ^^

:211:14 note: 'uv' previously declared here
@location(2) uv: vec2<f32>,
```

## Solution

Rename the shader variable `uv` to `viewport_uv` to prevent variable
redeclaration error.
2023-05-25 21:54:29 +00:00
Robin KAY
d74533b407
Add support for custom glTF vertex attributes. (#5370)
# Objective

The objective is to be able to load data from "application-specific"
(see glTF spec 3.7.2.1.) vertex attribute semantics from glTF files into
Bevy meshes.

## Solution

Rather than probe the glTF for the specific attributes supported by
Bevy, this PR changes the loader to iterate through all the attributes
and map them onto `MeshVertexAttribute`s. This mapping includes all the
previously supported attributes, plus it is now possible to add mappings
using the `add_custom_vertex_attribute()` method on `GltfPlugin`.

## Changelog

- Add support for loading custom vertex attributes from glTF files.
- Add the `custom_gltf_vertex_attribute.rs` example to illustrate
loading custom vertex attributes.

## Migration Guide

- If you were instantiating `GltfPlugin` using the unit-like struct
syntax, you must instead use `GltfPlugin::default()` as the type is no
longer unit-like.
2023-04-24 14:20:13 +00:00
IceSentry
c7eaedd6a1
Remove old post_processing example (#8376)
# Objective

- The old post processing example doesn't use the actual post processing
features of bevy. It also has some issues with resizing. It's also
causing some confusion for people because accessing the prepass textures
from it is not easy.
- There's already a render to texture example
- At this point, it's mostly obsolete since the post_process_pass
example is more complete and shows the recommended way to do post
processing in bevy. It's a bit more complicated, but it's well
documented and I'm working on simplifying it even more

## Solution

- Remove the old post_processing example
- Rename post_process_pass to post_processing


## Reviewer Notes
The diff is really noisy because of the rename, but I didn't change any
code in the example.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2023-04-15 21:48:31 +00:00
Nicola Papale
8df014fbaf
Add parallax mapping to bevy PBR (#5928)
# Objective

Add a [parallax mapping] shader to bevy. Please note that
this is a 3d technique, NOT a 2d sidescroller feature.

## Solution

- Add related fields to `StandardMaterial`
- update the pbr shader
- Add an example taking advantage of parallax mapping

A pre-existing implementation exists at:
https://github.com/nicopap/bevy_mod_paramap/

The implementation is derived from:

https://web.archive.org/web/20150419215321/http://sunandblackcat.com/tipFullView.php?l=eng&topicid=28

Further discussion on literature is found in the `bevy_mod_paramap`
README.

### Limitations

- The mesh silhouette isn't affected by the depth map.
- The depth of the pixel does not reflect its visual position, resulting
  in artifacts for depth-dependent features such as fog or SSAO
- GLTF does not define a height map texture, so somehow the user will
  always need to work around this limitation, though [an extension is in
  the works][gltf]

### Future work

- It's possible to update the depth in the depth buffer to follow the
  parallaxed texture. This would enable interop with depth-based
  visual effects, it also allows `discard`ing pixels of materials when
  computed depth is higher than the one in depth buffer
- Cheap lower quality single-sample method using [offset limiting]
- Add distance fading, to disable parallaxing (relatively expensive)
  on distant objects
- GLTF extension to allow defining height maps. Or a workaround
  implemented through a blender plugin to the GLTF exporter that
  uses the `extras` field to add height map.
- [Quadratic surface vertex attributes][oliveira_3] to enable parallax
  mapping on bending surfaces and allow clean silhouetting.
- noise based sampling, to limit the pancake artifacts.
- Cone mapping ([GPU gems], [Simcity (2013)][simcity]). Requires
  preprocessing, increase depth map size, reduces sample count greatly.
- [Quadtree parallax mapping][qpm] (also requires preprocessing)
- Self-shadowing of parallax-mapped surfaces by modifying the shadow map
- Generate depth map from normal map [link to slides], [blender
question]


https://user-images.githubusercontent.com/26321040/223563792-dffcc6ab-70e8-4ff9-90d1-b36c338695ad.mp4

[blender question]:
https://blender.stackexchange.com/questions/89278/how-to-get-a-smooth-curvature-map-from-a-normal-map
[link to slides]:
https://developer.download.nvidia.com/assets/gamedev/docs/nmap2displacement.pdf
[oliveira_3]:
https://www.inf.ufrgs.br/~oliveira/pubs_files/Oliveira_Policarpo_RP-351_Jan_2005.pdf
[GPU gems]:
https://developer.nvidia.com/gpugems/gpugems3/part-iii-rendering/chapter-18-relaxed-cone-stepping-relief-mapping
[simcity]:
https://community.simtropolis.com/omnibus/other-games/building-and-rendering-simcity-2013-r247/
[offset limiting]:
https://raw.githubusercontent.com/marcusstenbeck/tncg14-parallax-mapping/master/documents/Parallax%20Mapping%20with%20Offset%20Limiting%20-%20A%20Per-Pixel%20Approximation%20of%20Uneven%20Surfaces.pdf
[gltf]: https://github.com/KhronosGroup/glTF/pull/2196
[qpm]:
https://www.gamedevs.org/uploads/quadtree-displacement-mapping-with-height-blending.pdf

---

## Changelog

- Add a `depth_map` field to the `StandardMaterial`, it is a grayscale
  image where white represents bottom and black the top. If `depth_map`
  is set, bevy's pbr shader will use it to do [parallax mapping] to
  give an increased feel of depth to the material. This is similar to a
  displacement map, but with infinite precision at fairly low cost.
- The fields `parallax_mapping_method`, `parallax_depth_scale` and
  `max_parallax_layer_count` allow finer grained control over the
  behavior of the parallax shader.
- Add the `parallax_mapping` example to show off the effect.

[parallax mapping]: https://en.wikipedia.org/wiki/Parallax_mapping

---------

Co-authored-by: Robert Swain <robert.swain@gmail.com>
2023-04-15 10:25:14 +00:00
JMS55
53667dea56
Temporal Antialiasing (TAA) (#7291)
![image](https://user-images.githubusercontent.com/47158642/214374911-412f0986-3927-4f7a-9a6c-413bdee6b389.png)

# Objective

- Implement an alternative antialias technique
- TAA scales based off of view resolution, not geometry complexity
- TAA filters textures, firefly pixels, and other aliasing not covered
by MSAA
- TAA additionally will reduce noise / increase quality in future
stochastic rendering techniques
- Closes https://github.com/bevyengine/bevy/issues/3663

## Solution

- Add a temporal jitter component
- Add a motion vector prepass
- Add a TemporalAntialias component and plugin
- Combine existing MSAA and FXAA examples and add TAA

## Followup Work
- Prepass motion vector support for skinned meshes
- Move uniforms needed for motion vectors into a separate bind group,
instead of using different bind group layouts
- Reuse previous frame's GPU view buffer for motion vectors, instead of
recomputing
- Mip biasing for sharper textures, and or unjitter texture UVs
https://github.com/bevyengine/bevy/issues/7323
- Compute shader for better performance
- Investigate FSR techniques
  - Historical depth based disocclusion tests, for geometry disocclusion
  - Historical luminance/hue based tests, for shading disocclusion
- Pixel "locks" to reduce blending rate / revamp history confidence
mechanism
- Orthographic camera support for TemporalJitter
- Figure out COD's 1-tap bicubic filter

---

## Changelog

- Added MotionVectorPrepass and TemporalJitter
- Added TemporalAntialiasPlugin, TemporalAntialiasBundle, and
TemporalAntialiasSettings

---------

Co-authored-by: IceSentry <c.giguere42@gmail.com>
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: Daniel Chia <danstryder@gmail.com>
Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
Co-authored-by: Brandon Dyer <brandondyer64@gmail.com>
Co-authored-by: Edgar Geier <geieredgar@gmail.com>
2023-03-27 22:22:40 +00:00
Francesco
7b38de0a64
(De) serialize resources in scenes (#6846)
# Objective

Co-Authored-By: davier
[bricedavier@gmail.com](mailto:bricedavier@gmail.com)
Fixes #3576.
Adds a `resources` field in scene serialization data to allow
de/serializing resources that have reflection enabled.

## Solution

Most of this code is taken from a previous closed PR:
https://github.com/bevyengine/bevy/pull/3580. Most of the credit goes to
@Davier , what I did was mostly getting it to work on the latest main
branch of Bevy, along with adding a few asserts in the currently
existing tests to be sure everything is working properly.

This PR changes the scene format to include resources in this way:
```
(
  resources: {
    // List of resources here, keyed by resource type name.
  },
  entities: [
    // Previous scene format here
  ],
)
```

An example taken from the tests:
```
(
  resources: {
    "bevy_scene::serde::tests::MyResource": (
      foo: 123,
    ),
  },
  entities: {
    // Previous scene format here
  },
)
```
For this, a `resources` fields has been added on the `DynamicScene` and
the `DynamicSceneBuilder` structs. The latter now also has a method
named `extract_resources` to properly extract the existing resources
registered in the local type registry, in a similar way to
`extract_entities`.


---

## Changelog


Added: Reflect resources registered in the type registry used by dynamic
scenes will now be properly de/serialized in scene data.

## Migration Guide

Since the scene format has been changed, the user may not be able to use
scenes saved prior to this PR due to the `resources` scene field being
missing. ~~To preserve backwards compatibility, I will try to make the
`resources` fully optional so that old scenes can be loaded without
issue.~~

## TODOs

- [x] I may have to update a few doc blocks still referring to dynamic
scenes as mere container of entities, since they now include resources
as well.
- [x] ~~I want to make the `resources` key optional, as specified in the
Migration Guide, so that old scenes will be compatible with this
change.~~ Since this would only be trivial for ron format, I think it
might be better to consider it in a separate PR/discussion to figure out
if it could be done for binary serialization too.
- [x] I suppose it might be a good idea to add a resources in the scene
example so that users will quickly notice they can serialize resources
just like entities.

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2023-03-20 21:17:02 +00:00
IceSentry
9d1193df6c
Add low level post process example using a custom render pass (#6909)
Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
Co-authored-by: Robert Swain <robert.swain@gmail.com>
2023-03-16 03:22:17 +00:00
IceSentry
71cf35ce42 Allow prepass in webgl (#7537)
# Objective

- Use the prepass textures in webgl

## Solution

- Bind the prepass textures even when using webgl, but only if msaa is disabled
- Also did some refactors to centralize how textures are bound, similar to the EnvironmentMapLight PR
- ~~Also did some refactors of the example to make it work in webgl~~
- ~~To make the example work in webgl, I needed to use a sampler for the depth texture, the resulting code looks a bit weird, but it's simple enough and I think it's worth it to show how it works when using webgl~~
2023-03-02 02:23:06 +00:00
Griffin
912fb58869 Initial tonemapping options (#7594)
# Objective

Splits tone mapping from https://github.com/bevyengine/bevy/pull/6677 into a separate PR.
Address https://github.com/bevyengine/bevy/issues/2264.
Adds tone mapping options:
- None: Bypasses tonemapping for instances where users want colors output to match those set.
- Reinhard
- Reinhard Luminance: Bevy's exiting tonemapping
- [ACES](https://github.com/TheRealMJP/BakingLab/blob/master/BakingLab/ACES.hlsl) (Fitted version, based on the same implementation that Godot 4 uses) see https://github.com/bevyengine/bevy/issues/2264
- [AgX](https://github.com/sobotka/AgX)
- SomewhatBoringDisplayTransform
- TonyMcMapface
- Blender Filmic

This PR also adds support for EXR images so they can be used to compare tonemapping options with reference images.

## Migration Guide
- Tonemapping is now an enum with NONE and the various tonemappers.
- The DebandDither is now a separate component.




Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
2023-02-19 20:38:13 +00:00
JMS55
dd4299bcf9 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
Aevyrie
f3a23fd569 Fix array_texture example (#7543)
# Objective

- Shader error cause by a missing import.
- `pbr_functions.wgsl` was missing an import for the `ambient_light()` function, as `array_texture` doesn't import it.
- Closes #7542.

## Solution

- Add`#import bevy_pbr::pbr_ambient` into `array_texture`
2023-02-07 09:14:15 +00:00
Robert Swain
8b7ebe1738 Fix post_processing and shader_prepass examples (#7419)
# Objective

- Fix `post_processing` and `shader_prepass` examples as they fail when compiling shaders due to missing shader defs
- Fixes #6799
- Fixes #6996
- Fixes #7375 
- Supercedes #6997
- Supercedes #7380 

## Solution

- The prepass was broken due to a missing `MAX_CASCADES_PER_LIGHT` shader def. Add it.
- The shader used in the `post_processing` example is applied to a 2D mesh, so use the correct mesh2d_view_bindings shader import.
2023-01-30 22:53:08 +00:00
Rob Parrett
c673343e05 Fix missing import in array_texture example (#7418)
# Objective

Fixes #7417 

## Solution

Just adds the missing `bevy_pbr::fog` import.
2023-01-30 03:22:29 +00:00
Marco Buono
1a96d820fd Add Distance and Atmospheric Fog support (#6412)
<img width="1392" alt="image" src="https://user-images.githubusercontent.com/418473/203873533-44c029af-13b7-4740-8ea3-af96bd5867c9.png">
<img width="1392" alt="image" src="https://user-images.githubusercontent.com/418473/203873549-36be7a23-b341-42a2-8a9f-ceea8ac7a2b8.png">


# Objective

- Add support for the “classic” distance fog effect, as well as a more advanced atmospheric fog effect.

## Solution

This PR:

- Introduces a new `FogSettings` component that controls distance fog per-camera. 
- Adds support for three widely used “traditional” fog falloff modes: `Linear`, `Exponential` and `ExponentialSquared`, as well as a more advanced `Atmospheric` fog;
- Adds support for directional light influence over fog color;
- Extracts fog via `ExtractComponent`, then uses a prepare system that sets up a new dynamic uniform struct (`Fog`), similar to other mesh view types;
- Renders fog in PBR material shader, as a final adjustment to the `output_color`, after PBR is computed (but before tone mapping);
- Adds a new `StandardMaterial` flag to enable fog; (`fog_enabled`)
- Adds convenience methods for easier artistic control when creating non-linear fog types;
- Adds documentation around fog.

---

## Changelog

### Added

- Added support for distance-based fog effects for PBR materials, controllable per-camera via the new `FogSettings` component;
- Added `FogFalloff` enum for selecting between three widely used “traditional” fog falloff modes: `Linear`, `Exponential` and `ExponentialSquared`, as well as a more advanced `Atmospheric` fog;
2023-01-29 15:28:56 +00:00
研究社交
adae877be2 Use only one sampler in the array texture example. (#7405)
# Objective

Fixes #7373 

## Solution

Use only one sampler instead of an array of samplers.
2023-01-29 15:08:21 +00:00
研究社交
6b38863313 Request WGPU Capabilities for Non-uniform Indexing (#6995)
# Objective

Fixes #6952 

## Solution

- Request WGPU capabilities `SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING`, `SAMPLER_NON_UNIFORM_INDEXING` and `UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING` when corresponding features are enabled.
- Add an example (`shaders/texture_binding_array`) illustrating (and testing) the use of non-uniform indexed textures and samplers.

![image](https://user-images.githubusercontent.com/16053640/209448310-defa4eae-6bcb-460d-9b3d-a3d2fad4316c.png)

## Changelog

- Added new capabilities for shader validation.
- Added example `shaders/texture_binding_array`.
2023-01-26 13:18:15 +00:00
IceSentry
3c63c0dab7 Move prepass functions to prepass_utils (#7354)
# Objective

- The functions added to utils.wgsl by the prepass assume that mesh_view_bindings are present, which isn't always the case
- Fixes https://github.com/bevyengine/bevy/issues/7353

## Solution

- Move these functions to their own `prepass_utils.wgsl` file


Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
2023-01-24 20:36:40 +00:00
IceSentry
b3224e135b Add depth and normal prepass (#6284)
# Objective

- Add a configurable prepass
- A depth prepass is useful for various shader effects and to reduce overdraw. It can be expansive depending on the scene so it's important to be able to disable it if you don't need any effects that uses it or don't suffer from excessive overdraw.
- The goal is to eventually use it for things like TAA, Ambient Occlusion, SSR and various other techniques that can benefit from having a prepass.

## Solution

The prepass node is inserted before the main pass. It runs for each `Camera3d` with a prepass component (`DepthPrepass`, `NormalPrepass`). The presence of one of those components is used to determine which textures are generated in the prepass. When any prepass is enabled, the depth buffer generated will be used by the main pass to reduce overdraw.

The prepass runs for each `Material` created with the `MaterialPlugin::prepass_enabled` option set to `true`. You can overload the shader used by the prepass by using `Material::prepass_vertex_shader()` and/or `Material::prepass_fragment_shader()`. It will also use the `Material::specialize()` for more advanced use cases. It is enabled by default on all materials.

The prepass works on opaque materials and materials using an alpha mask. Transparent materials are ignored.

The `StandardMaterial` overloads the prepass fragment shader to support alpha mask and normal maps.

---

## Changelog

- Add a new `PrepassNode` that runs before the main pass
- Add a `PrepassPlugin` to extract/prepare/queue the necessary data
- Add a `DepthPrepass` and `NormalPrepass` component to control which textures will be created by the prepass and available in later passes.
- Add a new `prepass_enabled` flag to the `MaterialPlugin` that will control if a material uses the prepass or not.
- Add a new `prepass_enabled` flag to the `PbrPlugin` to control if the StandardMaterial uses the prepass. Currently defaults to false.
- Add `Material::prepass_vertex_shader()` and `Material::prepass_fragment_shader()` to control the prepass from the `Material`

## Notes

In bevy's sample 3d scene, the performance is actually worse when enabling the prepass, but on more complex scenes the performance is generally better. I would like more testing on this, but @DGriffin91 has reported a very noticeable improvements in some scenes.

The prepass is also used by @JMS55 for TAA and GTAO

discord thread: <https://discord.com/channels/691052431525675048/1011624228627419187>

This PR was built on top of the work of multiple people

Co-Authored-By: @superdump 
Co-Authored-By: @robtfm 
Co-Authored-By: @JMS55 

Co-authored-by: Charles <IceSentry@users.noreply.github.com>
Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
2023-01-19 22:11:13 +00:00
Yyee
dc09ee36e2 Add pixelated Bevy to assets and an example (#6408)
# Objective
Fixes #2279 

## Solution
Added pixelated Bevy to assets folder and used in a `pixel_perfect` example.
2022-11-14 22:15:46 +00:00
Robert Swain
fc56c686af bevy_pbr: Fix incorrect and unnecessary normal-mapping code (#5766)
# Objective

- Fixes #4019 
- Fix lighting of double-sided materials when using a negative scale
- The FlightHelmet.gltf model's hose uses a double-sided material. Loading the model with a uniform scale of -1.0, and comparing against Blender, it was identified that negating the world-space tangent, bitangent, and interpolated normal produces incorrect lighting. Discussion with Morten Mikkelsen clarified that this is both incorrect and unnecessary.

## Solution

- Remove the code that negates the T, B, and N vectors (the interpolated world-space tangent, calculated world-space bitangent, and interpolated world-space normal) when seeing the back face of a double-sided material with negative scale.
- Negate the world normal for a double-sided back face only when not using normal mapping

### Before, on `main`, flipping T, B, and N

<img width="932" alt="Screenshot 2022-08-22 at 15 11 53" src="https://user-images.githubusercontent.com/302146/185965366-f776ff2c-cfa1-46d1-9c84-fdcb399c273c.png">

### After, on this PR

<img width="932" alt="Screenshot 2022-08-22 at 15 12 11" src="https://user-images.githubusercontent.com/302146/185965420-8be493e2-3b1a-4188-bd13-fd6b17a76fe7.png">

### Double-sided material without normal maps

https://user-images.githubusercontent.com/302146/185988113-44a384e7-0b55-4946-9b99-20f8c803ab7e.mp4

---

## Changelog

- Fixed: Lighting of normal-mapped, double-sided materials applied to models with negative scale
- Fixed: Lighting and shadowing of back faces with no normal-mapping and a double-sided material

## Migration Guide

`prepare_normal` from the `bevy_pbr::pbr_functions` shader import has been reworked.

Before:
```rust
    pbr_input.world_normal = in.world_normal;

    pbr_input.N = prepare_normal(
        pbr_input.material.flags,
        in.world_normal,
#ifdef VERTEX_TANGENTS
#ifdef STANDARDMATERIAL_NORMAL_MAP
        in.world_tangent,
#endif
#endif
        in.uv,
        in.is_front,
    );
```

After:
```rust
    pbr_input.world_normal = prepare_world_normal(
        in.world_normal,
        (material.flags & STANDARD_MATERIAL_FLAGS_DOUBLE_SIDED_BIT) != 0u,
        in.is_front,
    );

    pbr_input.N = apply_normal_mapping(
        pbr_input.material.flags,
        pbr_input.world_normal,
#ifdef VERTEX_TANGENTS
#ifdef STANDARDMATERIAL_NORMAL_MAP
        in.world_tangent,
#endif
#endif
        in.uv,
    );
```
2022-11-03 20:37:32 +00:00
Gino Valente
bb968f41bc bevy_scene: Serialize entities to map (#6416)
# Objective

Entities are unique, however, this is not reflected in the scene format. Currently, entities are stored in a list where a user could inadvertently create a duplicate of the same entity. 

## Solution

Switch from the list representation to a map representation for entities.

---

## Changelog

* The `entities` field in the scene format is now a map of entity ID to entity data

## Migration Guide

The scene format now stores its collection of entities in a map rather than a list:

```rust
// OLD
(
  entities: [
    (
      entity: 12,
      components: {
        "bevy_transform::components::transform::Transform": (
          translation: (
            x: 0.0,
            y: 0.0,
            z: 0.0
          ),
          rotation: (0.0, 0.0, 0.0, 1.0),
          scale: (
            x: 1.0,
            y: 1.0,
            z: 1.0
          ),
        ),
      },
    ),
  ],
)

// NEW
(
  entities: {
    12: (
      components: {
        "bevy_transform::components::transform::Transform": (
          translation: (
            x: 0.0,
            y: 0.0,
            z: 0.0
          ),
          rotation: (0.0, 0.0, 0.0, 1.0),
          scale: (
            x: 1.0,
            y: 1.0,
            z: 1.0
          ),
        ),
      },
    ),
  },
)
```
2022-10-31 16:35:18 +00:00
Gino Valente
894334b51e bevy_scene: Use map for scene components (#6345)
# Objective

Currently scenes define components using a list:

```rust
[
  (
    entity: 0,
    components: [
      {
        "bevy_transform::components::transform::Transform": (
          translation: (
            x: 0.0,
            y: 0.0,
            z: 0.0
          ),
          rotation: (0.0, 0.0, 0.0, 1.0),
          scale: (
            x: 1.0,
            y: 1.0,
            z: 1.0
          ),
        ),
      },
      {
        "my_crate::Foo": (
          text: "Hello World",
        ),
      },
      {
        "my_crate::Bar": (
          baz: 123,
        ),
      },
    ],
  ),
]
```

However, this representation has some drawbacks (as pointed out by @Metadorius in [this](https://github.com/bevyengine/bevy/pull/4561#issuecomment-1202215565) comment):

1. Increased nesting and more characters (minor effect on overall size)
2. More importantly, by definition, entities cannot have more than one instance of any given component. Therefore, such data is best stored as a map— where all values are meant to have unique keys.


## Solution

Change `components` to store a map of components rather than a list:

```rust
[
  (
    entity: 0,
    components: {
      "bevy_transform::components::transform::Transform": (
        translation: (
          x: 0.0,
          y: 0.0,
          z: 0.0
        ),
        rotation: (0.0, 0.0, 0.0, 1.0),
        scale: (
          x: 1.0,
          y: 1.0,
          z: 1.0
        ),
      ),
      "my_crate::Foo": (
        text: "Hello World",
      ),
      "my_crate::Bar": (
        baz: 123
      ),
    },
  ),
]
```

#### Code Representation

This change only affects the scene format itself. `DynamicEntity` still stores its components as a list. The reason for this is that storing such data as a map is not really needed since:
1. The "key" of each value is easily found by just calling `Reflect::type_name` on it
2. We should be generating such structs using the `World` itself which upholds the one-component-per-entity rule

One could in theory create manually create a `DynamicEntity` with duplicate components, but this isn't something I think we should focus on in this PR. `DynamicEntity` can be broken in other ways (i.e. storing a non-component in the components list), and resolving its issues can be done in a separate PR.

---

## Changelog

* The scene format now uses a map to represent the collection of components rather than a list

## Migration Guide

The scene format now uses a map to represent the collection of components. Scene files will need to update from the old list format.

<details>
<summary>Example Code</summary>

```rust
// OLD
[
  (
    entity: 0,
    components: [
      {
        "bevy_transform::components::transform::Transform": (
          translation: (
            x: 0.0,
            y: 0.0,
            z: 0.0
          ),
          rotation: (0.0, 0.0, 0.0, 1.0),
          scale: (
            x: 1.0,
            y: 1.0,
            z: 1.0
          ),
        ),
      },
      {
        "my_crate::Foo": (
          text: "Hello World",
        ),
      },
      {
        "my_crate::Bar": (
          baz: 123,
        ),
      },
    ],
  ),
]

// NEW
[
  (
    entity: 0,
    components: {
      "bevy_transform::components::transform::Transform": (
        translation: (
          x: 0.0,
          y: 0.0,
          z: 0.0
        ),
        rotation: (0.0, 0.0, 0.0, 1.0),
        scale: (
          x: 1.0,
          y: 1.0,
          z: 1.0
        ),
      ),
      "my_crate::Foo": (
        text: "Hello World",
      ),
      "my_crate::Bar": (
        baz: 123
      ),
    },
  ),
]
```

</details>
2022-10-27 01:46:33 +00:00
Gino Valente
beab0bdc63 bevy_scene: Replace root list with struct (#6354)
# Objective

Scenes are currently represented as a list of entities. This is all we need currently, but we may want to add more data to this format in the future (metadata, asset lists, etc.). 

It would be nice to update the format in preparation of possible future changes. Doing so now (i.e., before 0.9) could mean reduced[^1] breakage for things added in 0.10.

[^1]: Obviously, adding features runs the risk of breaking things regardless. But if all features added are for whatever reason optional or well-contained, then users should at least have an easier time updating.

## Solution

Made the scene root a struct rather than a list.

```rust
(
  entities: [
    // Entity data here...
  ]
)
```

---

## Changelog

* The scene format now puts the entity list in a newly added `entities` field, rather than having it be the root object

## Migration Guide

The scene file format now uses a struct as the root object rather than a list of entities. The list of entities is now found in the `entities` field of this struct.

```rust
// OLD
[
  (
    entity: 0,
    components: [
      // Components...
    ]
  ),
]

// NEW
(
  entities: [
    (
      entity: 0,
      components: [
        // Components...
      ]
    ),
  ]
)
```


Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2022-10-24 21:01:11 +00:00
Charles
8073362039 add globals to mesh view bind group (#5409)
# Objective

- It's often really useful to have access to the time when writing shaders.

## Solution

- Add a UnifformBuffer in the mesh view bind group
- This buffer contains the time, delta time and a wrapping frame count

https://user-images.githubusercontent.com/8348954/180130314-97948c2a-2d11-423d-a9c4-fb5c9d1892c7.mp4

---

## Changelog

- Added a `GlobalsUniform` at position 9 of the mesh view bind group

## Notes

The implementation is currently split between bevy_render and bevy_pbr because I was basing my implementation on the `ViewPlugin`. I'm not sure if that's the right way to structure it.

I named this `globals` instead of just time because we could potentially add more things to it.

## References in other engines

- Godot: <https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/canvas_item_shader.html#global-built-ins>
    - Global time since startup, in seconds, by default resets to 0 after 3600 seconds
    - Doesn't seem to have anything else
- Unreal: <https://docs.unrealengine.com/4.26/en-US/RenderingAndGraphics/Materials/ExpressionReference/Constant/>
    - Generic time value that updates every frame. Can be paused or scaled.
    - Frame count node, doesn't seem to be an equivalent for shaders: <https://docs.unrealengine.com/4.26/en-US/BlueprintAPI/Utilities/GetFrameCount/>
- Unity: <https://docs.unity3d.com/Manual/SL-UnityShaderVariables.html>
    - time since startup in seconds. No mention of time wrapping. Stored as a `vec4(t/20, t, t*2, t*3)` where `t` is the value in seconds
    - Also has delta time, sin time and cos time
- ShaderToy: <https://www.shadertoy.com/howto>
    - iTime is the time since startup in seconds.
    - iFrameRate
    - iTimeDelta
    - iFrame frame counter

Co-authored-by: Charles <IceSentry@users.noreply.github.com>
2022-09-28 04:20:27 +00:00
Gino Valente
d30d3e752a bevy_reflect: Improve serialization format even more (#5723)
> Note: This is rebased off #4561 and can be viewed as a competitor to that PR. See `Comparison with #4561` section for details.

# Objective

The current serialization format used by `bevy_reflect` is both verbose and error-prone. Taking the following structs[^1] for example:

```rust
// -- src/inventory.rs

#[derive(Reflect)]
struct Inventory {
  id: String,
  max_storage: usize,
  items: Vec<Item>
}

#[derive(Reflect)]
struct Item {
  name: String
}
```

Given an inventory of a single item, this would serialize to something like:

```rust
// -- assets/inventory.ron

{
  "type": "my_game::inventory::Inventory",
  "struct": {
    "id": {
      "type": "alloc::string::String",
      "value": "inv001",
    },
    "max_storage": {
      "type": "usize",
      "value": 10
    },
    "items": {
      "type": "alloc::vec::Vec<alloc::string::String>",
      "list": [
        {
          "type": "my_game::inventory::Item",
          "struct": {
            "name": {
              "type": "alloc::string::String",
              "value": "Pickaxe"
            },
          },
        },
      ],
    },
  },
}
```

Aside from being really long and difficult to read, it also has a few "gotchas" that users need to be aware of if they want to edit the file manually. A major one is the requirement that you use the proper keys for a given type. For structs, you need `"struct"`. For lists, `"list"`. For tuple structs, `"tuple_struct"`. And so on.

It also ***requires*** that the `"type"` entry come before the actual data. Despite being a map— which in programming is almost always orderless by default— the entries need to be in a particular order. Failure to follow the ordering convention results in a failure to deserialize the data.

This makes it very prone to errors and annoyances.


## Solution

Using #4042, we can remove a lot of the boilerplate and metadata needed by this older system. Since we now have static access to type information, we can simplify our serialized data to look like:

```rust
// -- assets/inventory.ron

{
  "my_game::inventory::Inventory": (
    id: "inv001",
    max_storage: 10,
    items: [
      (
        name: "Pickaxe"
      ),
    ],
  ),
}
```

This is much more digestible and a lot less error-prone (no more key requirements and no more extra type names).

Additionally, it is a lot more familiar to users as it follows conventional serde mechanics. For example, the struct is represented with `(...)` when serialized to RON.

#### Custom Serialization

Additionally, this PR adds the opt-in ability to specify a custom serde implementation to be used rather than the one created via reflection. For example[^1]:

```rust
// -- src/inventory.rs

#[derive(Reflect, Serialize)]
#[reflect(Serialize)]
struct Item {
  #[serde(alias = "id")]
  name: String
}
```

```rust
// -- assets/inventory.ron

{
  "my_game::inventory::Inventory": (
    id: "inv001",
    max_storage: 10,
    items: [
      (
        id: "Pickaxe"
      ),
    ],
  ),
},
```

By allowing users to define their own serialization methods, we do two things:

1. We give more control over how data is serialized/deserialized to the end user
2. We avoid having to re-define serde's attributes and forcing users to apply both (e.g. we don't need a `#[reflect(alias)]` attribute).

### Improved Formats

One of the improvements this PR provides is the ability to represent data in ways that are more conventional and/or familiar to users. Many users are familiar with RON so here are some of the ways we can now represent data in RON:

###### Structs

```js
{
  "my_crate::Foo": (
    bar: 123
  )
}
// OR
{
  "my_crate::Foo": Foo(
    bar: 123
  )
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::Foo",
  "struct": {
    "bar": {
      "type": "usize",
      "value": 123
    }
  }
}
```

</details>

###### Tuples

```js
{
  "(f32, f32)": (1.0, 2.0)
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "(f32, f32)",
  "tuple": [
    {
      "type": "f32",
      "value": 1.0
    },
    {
      "type": "f32",
      "value": 2.0
    }
  ]
}
```

</details>

###### Tuple Structs

```js
{
  "my_crate::Bar": ("Hello World!")
}
// OR
{
  "my_crate::Bar": Bar("Hello World!")
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::Bar",
  "tuple_struct": [
    {
      "type": "alloc::string::String",
      "value": "Hello World!"
    }
  ]
}
```

</details>

###### Arrays

It may be a bit surprising to some, but arrays now also use the tuple format. This is because they essentially _are_ tuples (a sequence of values with a fixed size), but only allow for homogenous types. Additionally, this is how RON handles them and is probably a result of the 32-capacity limit imposed on them (both by [serde](https://docs.rs/serde/latest/serde/trait.Serialize.html#impl-Serialize-for-%5BT%3B%2032%5D) and by [bevy_reflect](https://docs.rs/bevy/latest/bevy/reflect/trait.GetTypeRegistration.html#impl-GetTypeRegistration-for-%5BT%3B%2032%5D)).

```js
{
  "[i32; 3]": (1, 2, 3)
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "[i32; 3]",
  "array": [
    {
      "type": "i32",
      "value": 1
    },
    {
      "type": "i32",
      "value": 2
    },
    {
      "type": "i32",
      "value": 3
    }
  ]
}
```

</details>

###### Enums

To make things simple, I'll just put a struct variant here, but the style applies to all variant types:

```js
{
  "my_crate::ItemType": Consumable(
    name: "Healing potion"
  )
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::ItemType",
  "enum": {
    "variant": "Consumable",
    "struct": {
      "name": {
        "type": "alloc::string::String",
        "value": "Healing potion"
      }
    }
  }
}
```

</details>

### Comparison with #4561

This PR is a rebased version of #4561. The reason for the split between the two is because this PR creates a _very_ different scene format. You may notice that the PR descriptions for either PR are pretty similar. This was done to better convey the changes depending on which (if any) gets merged first. If #4561 makes it in first, I will update this PR description accordingly.

---

## Changelog

* Re-worked serialization/deserialization for reflected types
* Added `TypedReflectDeserializer` for deserializing data with known `TypeInfo`
* Renamed `ReflectDeserializer` to `UntypedReflectDeserializer` 
* ~~Replaced usages of `deserialize_any` with `deserialize_map` for non-self-describing formats~~ Reverted this change since there are still some issues that need to be sorted out (in a separate PR). By reverting this, crates like `bincode` can throw an error when attempting to deserialize non-self-describing formats (`bincode` results in `DeserializeAnyNotSupported`)
* Structs, tuples, tuple structs, arrays, and enums are now all de/serialized using conventional serde methods

## Migration Guide

* This PR reduces the verbosity of the scene format. Scenes will need to be updated accordingly:

```js
// Old format
{
  "type": "my_game::item::Item",
  "struct": {
    "id": {
      "type": "alloc::string::String",
      "value": "bevycraft:stone",
    },
    "tags": {
      "type": "alloc::vec::Vec<alloc::string::String>",
      "list": [
        {
          "type": "alloc::string::String",
          "value": "material"
        },
      ],
    },
}

// New format
{
  "my_game::item::Item": (
    id: "bevycraft:stone",
    tags: ["material"]
  )
}
```

[^1]: Some derives omitted for brevity.
2022-09-20 19:38:18 +00:00
robtfm
503c2a9677 adjust cluster index for viewport origin (#5947)
# Objective

fixes #5946

## Solution

adjust cluster index calculation for viewport origin.

from reading point 2 of the rasterization algorithm description in https://gpuweb.github.io/gpuweb/#rasterization, it looks like framebuffer space (and so @bulitin(position)) is not meant to be adjusted for viewport origin, so we need to subtract that to get the right cluster index.

- add viewport origin to rust `ExtractedView` and wgsl `View` structs
- subtract from frag coord for cluster index calculation
2022-09-15 21:58:14 +00:00
Tristan Guichaoua
e8439bf827 fix Quat type name in scene example scene file (#5803)
# Objective

fix #5790 

## Solution

Change type name in the scene file by its new name `glam::f32::sse2::quat::Quat`.
2022-08-29 23:56:42 +00:00
Tomasz Galkowski
04538fd802 fixes the types for Vec3 and Quat in scene example to remove WARN from the logs (#5751)
# Objective
- Fixes #5745.

## Solution
- Changes the Vec3 and Quat types.
2022-08-20 19:55:53 +00:00
Robert Swain
05e5008624 Support array / cubemap / cubemap array textures in KTX2 (#5325)
# Objective

- Fix / support KTX2 array / cubemap / cubemap array textures
- Fixes #4495 . Supersedes #4514 .

## Solution

- Add `Option<TextureViewDescriptor>` to `Image` to enable configuration of the `TextureViewDimension` of a texture.
  - This allows users to set `D2Array`, `D3`, `Cube`, `CubeArray` or whatever they need
  - Automatically configure this when loading KTX2
- Transcode all layers and faces instead of just one
- Use the UASTC block size of 128 bits, and the number of blocks in x/y for a given mip level in order to determine the offset of the layer and face within the KTX2 mip level data
- `wgpu` wants data ordered as layer 0 mip 0..n, layer 1 mip 0..n, etc. See https://docs.rs/wgpu/latest/wgpu/util/trait.DeviceExt.html#tymethod.create_texture_with_data
- Reorder the data KTX2 mip X layer Y face Z to `wgpu` layer Y face Z mip X order
- Add a `skybox` example to demonstrate / test loading cubemaps from PNG and KTX2, including ASTC 4x4, BC7, and ETC2 compression for support everywhere. Note that you need to enable the `ktx2,zstd` features to be able to load the compressed textures.

---

## Changelog

- Fixed: KTX2 array / cubemap / cubemap array textures
- Fixes: Validation failure for compressed textures stored in KTX2 where the width/height are not a multiple of the block dimensions.
- Added: `Image` now has an `Option<TextureViewDescriptor>` field to enable configuration of the texture view. This is useful for configuring the `TextureViewDimension` when it is not just a plain 2D texture and the loader could/did not identify what it should be.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-07-30 07:02:58 +00:00
Niklas Eicker
2b93ab5812 Remove unused code in game of life shader (#5349)
# Objective

- Make `game_of_life.wgsl` easier to read and understand

## Solution

- Remove unused code in the shader
    - `location_f32` was unused in `init`
    - `color` was unused in `update`
2022-07-17 15:24:24 +00:00
Niklas Eicker
71368d4ebe Fix line material shader (#5348)
# Objective

- The line shader missed the wgpu 0.13 update (#5168) and does not work in it's current state

## Solution

- update the shader
2022-07-17 15:02:57 +00:00
Charles
6b34e81f00 add a 3d lines example (#5319)
# Objective

- Showcase how to use a `Material` and `Mesh` to spawn 3d lines

![image](https://user-images.githubusercontent.com/8348954/179034236-ebc07f90-3eb5-46cc-8fc1-be7e6bf983fb.png)

## Solution

- Add an example using a simple `Material` and `Mesh` definition to draw a 3d line
	- Shows how to use `LineList` and `LineStrip` in combination with a specialized `Material`

## Notes

This isn't just a primitive shape because it needs a special Material, but I think it's a good showcase of the power of the `Material` and `AsBindGroup` abstractions. All of this is easy to figure out when you know these options are a thing, but I think they are hard to discover which is why I think this should be an example and not shipped with bevy.

Co-authored-by: Charles <IceSentry@users.noreply.github.com>
2022-07-15 22:37:05 +00:00
François
814f8d1635 update wgpu to 0.13 (#5168)
# Objective

- Update wgpu to 0.13
- ~~Wait, is wgpu 0.13 released? No, but I had most of the changes already ready since playing with webgpu~~ well it has been released now
- Also update parking_lot to 0.12 and naga to 0.9

## Solution

- Update syntax for wgsl shaders https://github.com/gfx-rs/wgpu/blob/master/CHANGELOG.md#wgsl-syntax
- Add a few options, remove some references: https://github.com/gfx-rs/wgpu/blob/master/CHANGELOG.md#other-breaking-changes
- fragment inputs should now exactly match vertex outputs for locations, so I added exports for those to be able to reuse them https://github.com/gfx-rs/wgpu/pull/2704
2022-07-14 21:17:16 +00:00
Boutillier
6b073ee412 Update shader_material_glsl example to include texture sampling (#5215)
# Objective

Add texture sampling to the GLSL shader example, as naga does not support the commonly used sampler2d type.
Fixes #5059

## Solution

- Align the shader_material_glsl example behaviour with the shader_material example,  as the later includes texture sampling.
- Update the GLSL shader to do texture sampling the way naga supports it, and document the way naga does not support it.

## Changelog

- The shader_material_glsl example has been updated to demonstrate texture sampling using the GLSL shading language.


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-07-08 01:14:22 +00:00
Carter Anderson
747b0c69b0 Better Materials: AsBindGroup trait and derive, simpler Material trait (#5053)
# Objective

This PR reworks Bevy's Material system, making the user experience of defining Materials _much_ nicer. Bevy's previous material system leaves a lot to be desired:
* Materials require manually implementing the `RenderAsset` trait, which involves manually generating the bind group, handling gpu buffer data transfer, looking up image textures, etc. Even the simplest single-texture material involves writing ~80 unnecessary lines of code. This was never the long term plan.
* There are two material traits, which is confusing, hard to document, and often redundant: `Material` and `SpecializedMaterial`. `Material` implicitly implements `SpecializedMaterial`, and `SpecializedMaterial` is used in most high level apis to support both use cases. Most users shouldn't need to think about specialization at all (I consider it a "power-user tool"), so the fact that `SpecializedMaterial` is front-and-center in our apis is a miss.
* Implementing either material trait involves a lot of "type soup". The "prepared asset" parameter is particularly heinous: `&<Self as RenderAsset>::PreparedAsset`. Defining vertex and fragment shaders is also more verbose than it needs to be. 

## Solution

Say hello to the new `Material` system:

```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    #[texture(1)]
    #[sampler(2)]
    color_texture: Handle<Image>,
}
impl Material for CoolMaterial {
    fn fragment_shader() -> ShaderRef {
        "cool_material.wgsl".into()
    }
}
```

Thats it! This same material would have required [~80 lines of complicated "type heavy" code](https://github.com/bevyengine/bevy/blob/v0.7.0/examples/shader/shader_material.rs) in the old Material system. Now it is just 14 lines of simple, readable code.

This is thanks to a new consolidated `Material` trait and the new `AsBindGroup` trait / derive.

### The new `Material` trait

The old "split" `Material` and `SpecializedMaterial` traits have been removed in favor of a new consolidated `Material` trait. All of the functions on the trait are optional.

The difficulty of implementing `Material` has been reduced by simplifying dataflow and removing type complexity:

```rust
// Old
impl Material for CustomMaterial {
    fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
        Some(asset_server.load("custom_material.wgsl"))
    }

    fn alpha_mode(render_asset: &<Self as RenderAsset>::PreparedAsset) -> AlphaMode {
        render_asset.alpha_mode
    }
}

// New
impl Material for CustomMaterial {
    fn fragment_shader() -> ShaderRef {
        "custom_material.wgsl".into()
    }

    fn alpha_mode(&self) -> AlphaMode {
        self.alpha_mode
    }
}
```

Specialization is still supported, but it is hidden by default under the `specialize()` function (more on this later).

### The `AsBindGroup` trait / derive

The `Material` trait now requires the `AsBindGroup` derive. This can be implemented manually relatively easily, but deriving it will almost always be preferable. 

Field attributes like `uniform` and `texture` are used to define which fields should be bindings,
what their binding type is, and what index they should be bound at:

```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    #[texture(1)]
    #[sampler(2)]
    color_texture: Handle<Image>,
}
```

In WGSL shaders, the binding looks like this:

```wgsl
struct CoolMaterial {
    color: vec4<f32>;
};

[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
[[group(1), binding(1)]]
var color_texture: texture_2d<f32>;
[[group(1), binding(2)]]
var color_sampler: sampler;
```

Note that the "group" index is determined by the usage context. It is not defined in `AsBindGroup`. Bevy material bind groups are bound to group 1.

The following field-level attributes are supported:
* `uniform(BINDING_INDEX)`
    * The field will be converted to a shader-compatible type using the `ShaderType` trait, written to a `Buffer`, and bound as a uniform. It can also be derived for custom structs.
* `texture(BINDING_INDEX)`
    * This field's `Handle<Image>` will be used to look up the matching `Texture` gpu resource, which will be bound as a texture in shaders. The field will be assumed to implement `Into<Option<Handle<Image>>>`. In practice, most fields should be a `Handle<Image>` or `Option<Handle<Image>>`. If the value of an `Option<Handle<Image>>` is `None`, the new `FallbackImage` resource will be used instead. This attribute can be used in conjunction with a `sampler` binding attribute (with a different binding index).
* `sampler(BINDING_INDEX)`
    * Behaves exactly like the `texture` attribute, but sets the Image's sampler binding instead of the texture. 

Note that fields without field-level binding attributes will be ignored.
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    this_field_is_ignored: String,
}
```

As mentioned above, `Option<Handle<Image>>` is also supported:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    #[texture(1)]
    #[sampler(2)]
    color_texture: Option<Handle<Image>>,
}
```
This is useful if you want a texture to be optional. When the value is `None`, the `FallbackImage` will be used for the binding instead, which defaults to "pure white".

Field uniforms with the same binding index will be combined into a single binding:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    #[uniform(0)]
    roughness: f32,
}
```

In WGSL shaders, the binding would look like this:
```wgsl
struct CoolMaterial {
    color: vec4<f32>;
    roughness: f32;
};

[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
```

Some less common scenarios will require "struct-level" attributes. These are the currently supported struct-level attributes:
* `uniform(BINDING_INDEX, ConvertedShaderType)`
    * Similar to the field-level `uniform` attribute, but instead the entire `AsBindGroup` value is converted to `ConvertedShaderType`, which must implement `ShaderType`. This is useful if more complicated conversion logic is required.
* `bind_group_data(DataType)`
    * The `AsBindGroup` type will be converted to some `DataType` using `Into<DataType>` and stored as `AsBindGroup::Data` as part of the `AsBindGroup::as_bind_group` call. This is useful if data needs to be stored alongside the generated bind group, such as a unique identifier for a material's bind group. The most common use case for this attribute is "shader pipeline specialization".

The previous `CoolMaterial` example illustrating "combining multiple field-level uniform attributes with the same binding index" can
also be equivalently represented with a single struct-level uniform attribute:
```rust
#[derive(AsBindGroup)]
#[uniform(0, CoolMaterialUniform)]
struct CoolMaterial {
    color: Color,
    roughness: f32,
}

#[derive(ShaderType)]
struct CoolMaterialUniform {
    color: Color,
    roughness: f32,
}

impl From<&CoolMaterial> for CoolMaterialUniform {
    fn from(material: &CoolMaterial) -> CoolMaterialUniform {
        CoolMaterialUniform {
            color: material.color,
            roughness: material.roughness,
        }
    }
}
```

### Material Specialization

Material shader specialization is now _much_ simpler:

```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
#[bind_group_data(CoolMaterialKey)]
struct CoolMaterial {
    #[uniform(0)]
    color: Color,
    is_red: bool,
}

#[derive(Copy, Clone, Hash, Eq, PartialEq)]
struct CoolMaterialKey {
    is_red: bool,
}

impl From<&CoolMaterial> for CoolMaterialKey {
    fn from(material: &CoolMaterial) -> CoolMaterialKey {
        CoolMaterialKey {
            is_red: material.is_red,
        }
    }
}

impl Material for CoolMaterial {
    fn fragment_shader() -> ShaderRef {
        "cool_material.wgsl".into()
    }

    fn specialize(
        pipeline: &MaterialPipeline<Self>,
        descriptor: &mut RenderPipelineDescriptor,
        layout: &MeshVertexBufferLayout,
        key: MaterialPipelineKey<Self>,
    ) -> Result<(), SpecializedMeshPipelineError> {
        if key.bind_group_data.is_red {
            let fragment = descriptor.fragment.as_mut().unwrap();
            fragment.shader_defs.push("IS_RED".to_string());
        }
        Ok(())
    }
}
```

Setting `bind_group_data` is not required for specialization (it defaults to `()`). Scenarios like "custom vertex attributes" also benefit from this system:
```rust
impl Material for CustomMaterial {
    fn vertex_shader() -> ShaderRef {
        "custom_material.wgsl".into()
    }

    fn fragment_shader() -> ShaderRef {
        "custom_material.wgsl".into()
    }

    fn specialize(
        pipeline: &MaterialPipeline<Self>,
        descriptor: &mut RenderPipelineDescriptor,
        layout: &MeshVertexBufferLayout,
        key: MaterialPipelineKey<Self>,
    ) -> Result<(), SpecializedMeshPipelineError> {
        let vertex_layout = layout.get_layout(&[
            Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
            ATTRIBUTE_BLEND_COLOR.at_shader_location(1),
        ])?;
        descriptor.vertex.buffers = vec![vertex_layout];
        Ok(())
    }
}
```

### Ported `StandardMaterial` to the new `Material` system

Bevy's built-in PBR material uses the new Material system (including the AsBindGroup derive):

```rust
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "7494888b-c082-457b-aacf-517228cc0c22"]
#[bind_group_data(StandardMaterialKey)]
#[uniform(0, StandardMaterialUniform)]
pub struct StandardMaterial {
    pub base_color: Color,
    #[texture(1)]
    #[sampler(2)]
    pub base_color_texture: Option<Handle<Image>>,
    /* other fields omitted for brevity */
```

### Ported Bevy examples to the new `Material` system

The overall complexity of Bevy's "custom shader examples" has gone down significantly. Take a look at the diffs if you want a dopamine spike.

Please note that while this PR has a net increase in "lines of code", most of those extra lines come from added documentation. There is a significant reduction
in the overall complexity of the code (even accounting for the new derive logic).

---

## Changelog

### Added

* `AsBindGroup` trait and derive, which make it much easier to transfer data to the gpu and generate bind groups for a given type.

### Changed

* The old `Material` and `SpecializedMaterial` traits have been replaced by a consolidated (much simpler) `Material` trait. Materials no longer implement `RenderAsset`.
* `StandardMaterial` was ported to the new material system. There are no user-facing api changes to the `StandardMaterial` struct api, but it now implements `AsBindGroup` and `Material` instead of `RenderAsset` and `SpecializedMaterial`.

## Migration Guide
The Material system has been reworked to be much simpler. We've removed a lot of boilerplate with the new `AsBindGroup` derive and the `Material` trait is simpler as well!

### Bevy 0.7 (old)

```rust
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
    color: Color,
    color_texture: Handle<Image>,
}

#[derive(Clone)]
pub struct GpuCustomMaterial {
    _buffer: Buffer,
    bind_group: BindGroup,
}

impl RenderAsset for CustomMaterial {
    type ExtractedAsset = CustomMaterial;
    type PreparedAsset = GpuCustomMaterial;
    type Param = (SRes<RenderDevice>, SRes<MaterialPipeline<Self>>);
    fn extract_asset(&self) -> Self::ExtractedAsset {
        self.clone()
    }

    fn prepare_asset(
        extracted_asset: Self::ExtractedAsset,
        (render_device, material_pipeline): &mut SystemParamItem<Self::Param>,
    ) -> Result<Self::PreparedAsset, PrepareAssetError<Self::ExtractedAsset>> {
        let color = Vec4::from_slice(&extracted_asset.color.as_linear_rgba_f32());

        let byte_buffer = [0u8; Vec4::SIZE.get() as usize];
        let mut buffer = encase::UniformBuffer::new(byte_buffer);
        buffer.write(&color).unwrap();

        let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
            contents: buffer.as_ref(),
            label: None,
            usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
        });

        let (texture_view, texture_sampler) = if let Some(result) = material_pipeline
            .mesh_pipeline
            .get_image_texture(gpu_images, &Some(extracted_asset.color_texture.clone()))
        {
            result
        } else {
            return Err(PrepareAssetError::RetryNextUpdate(extracted_asset));
        };
        let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
            entries: &[
                BindGroupEntry {
                    binding: 0,
                    resource: buffer.as_entire_binding(),
                },
                BindGroupEntry {
                    binding: 0,
                    resource: BindingResource::TextureView(texture_view),
                },
                BindGroupEntry {
                    binding: 1,
                    resource: BindingResource::Sampler(texture_sampler),
                },
            ],
            label: None,
            layout: &material_pipeline.material_layout,
        });

        Ok(GpuCustomMaterial {
            _buffer: buffer,
            bind_group,
        })
    }
}

impl Material for CustomMaterial {
    fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
        Some(asset_server.load("custom_material.wgsl"))
    }

    fn bind_group(render_asset: &<Self as RenderAsset>::PreparedAsset) -> &BindGroup {
        &render_asset.bind_group
    }

    fn bind_group_layout(render_device: &RenderDevice) -> BindGroupLayout {
        render_device.create_bind_group_layout(&BindGroupLayoutDescriptor {
            entries: &[
                BindGroupLayoutEntry {
                    binding: 0,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Buffer {
                        ty: BufferBindingType::Uniform,
                        has_dynamic_offset: false,
                        min_binding_size: Some(Vec4::min_size()),
                    },
                    count: None,
                },
                BindGroupLayoutEntry {
                    binding: 1,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Texture {
                        multisampled: false,
                        sample_type: TextureSampleType::Float { filterable: true },
                        view_dimension: TextureViewDimension::D2Array,
                    },
                    count: None,
                },
                BindGroupLayoutEntry {
                    binding: 2,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Sampler(SamplerBindingType::Filtering),
                    count: None,
                },
            ],
            label: None,
        })
    }
}
```

### Bevy 0.8 (new)

```rust
impl Material for CustomMaterial {
    fn fragment_shader() -> ShaderRef {
        "custom_material.wgsl".into()
    }
}

#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
    #[uniform(0)]
    color: Color,
    #[texture(1)]
    #[sampler(2)]
    color_texture: Handle<Image>,
}
```

## Future Work

* Add support for more binding types (cubemaps, buffers, etc). This PR intentionally includes a bare minimum number of binding types to keep "reviewability" in check.
* Consider optionally eliding binding indices using binding names. `AsBindGroup` could pass in (optional?) reflection info as a "hint".
    * This would make it possible for the derive to do this:
        ```rust
        #[derive(AsBindGroup)]
        pub struct CustomMaterial {
            #[uniform]
            color: Color,
            #[texture]
            #[sampler]
            color_texture: Option<Handle<Image>>,
            alpha_mode: AlphaMode,
        }
        ```
    * Or this
        ```rust
        #[derive(AsBindGroup)]
        pub struct CustomMaterial {
            #[binding]
            color: Color,
            #[binding]
            color_texture: Option<Handle<Image>>,
            alpha_mode: AlphaMode,
        }
        ```
    * Or even this (if we flip to "include bindings by default")
        ```rust
        #[derive(AsBindGroup)]
        pub struct CustomMaterial {
            color: Color,
            color_texture: Option<Handle<Image>>,
            #[binding(ignore)]
            alpha_mode: AlphaMode,
        }
        ```
* If we add the option to define custom draw functions for materials (which could be done in a type-erased way), I think that would be enough to support extra non-material bindings. Worth considering!
2022-06-30 23:48:46 +00:00
DGriffin91
7d55414652 Use tone mapping in array_texture example (#5131)
# Objective

The array_texture example does not currently apply tone mapping:
![no_tonemapping](https://user-images.githubusercontent.com/33357138/176327061-4c404b62-d260-458d-b3cb-4671bd8c2735.PNG)

## Solution

Use tone mapping:
![with_tonemapping](https://user-images.githubusercontent.com/33357138/176327092-7aaeac85-0d95-4c7d-9d91-7fe46bed32c3.PNG)
2022-06-29 03:57:08 +00:00
Robert Swain
84991d34f3 Array texture example (#5077)
# Objective

- Make the reusable PBR shading functionality a little more reusable
  - Add constructor functions for `StandardMaterial` and `PbrInput` structs to populate them with default values
  - Document unclear `PbrInput` members
- Demonstrate how to reuse the bevy PBR shading functionality
- The final important piece from #3969 as the initial shot at making the PBR shader code reusable in custom materials

## Solution

- Add back and rework the 'old' `array_texture` example from pre-0.6.
- Create a custom shader material
  - Use a single array texture binding and sampler for the material bind group
  - Use a shader that calls `pbr()` from the `bevy_pbr::pbr_functions` import
- Spawn a row of cubes using the custom material
- In the shader, select the array texture layer to sample by using the world position x coordinate modulo the number of array texture layers

<img width="1392" alt="Screenshot 2022-06-23 at 12 28 05" src="https://user-images.githubusercontent.com/302146/175278593-2296f519-f577-4ece-81c0-d842283784a1.png">

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-06-28 00:58:50 +00:00
Robert Swain
b333386271 Add reusable shader functions for transforming position/normal/tangent (#4901)
# Objective

- Add reusable shader functions for transforming positions / normals / tangents between local and world / clip space for 2D and 3D so that they are done in a simple and correct way
- The next step in #3969 so check there for more details.

## Solution

- Add `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports
  - These contain `mesh_` and `mesh2d_` versions of the following functions:
    - `mesh_position_local_to_world`
    - `mesh_position_world_to_clip`
    - `mesh_position_local_to_clip`
    - `mesh_normal_local_to_world`
    - `mesh_tangent_local_to_world`
- Use them everywhere where it is appropriate
  - Notably not in the sprite and UI shaders where `mesh2d_position_world_to_clip` could have been used, but including all the functions depends on the mesh binding so I chose to not use the function there
- NOTE: The `mesh_` and `mesh2d_` functions are currently identical. However, if I had defined only `bevy_pbr::mesh_functions` and used that in bevy_sprite, then bevy_sprite would have a runtime dependency on bevy_pbr, which seems undesirable. I also expect that when we have a proper 2D rendering API, these functions will diverge between 2D and 3D.

---

## Changelog

- Added: `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports containing `mesh_` and `mesh2d_` versions of the following functions:
  - `mesh_position_local_to_world`
  - `mesh_position_world_to_clip`
  - `mesh_position_local_to_clip`
  - `mesh_normal_local_to_world`
  - `mesh_tangent_local_to_world`

## Migration Guide

- The `skin_tangents` function from the `bevy_pbr::skinning` shader import has been replaced with the `mesh_tangent_local_to_world` function from the `bevy_pbr::mesh_functions` shader import
2022-06-14 00:32:33 +00:00
Thierry Berger
765bd46c2e add a post-processing example (#4797)
# Objective

- Add an example showing a custom post processing effect, done after the first rendering pass.

## Solution

- A simple post processing "chromatic aberration" effect. I mixed together examples `3d/render_to_texture`, and `shader/shader_material_screenspace_texture`
- Reading a bit how https://github.com/bevyengine/bevy/pull/3430 was done gave me pointers to apply the main pass to the 2d render rather than using a 3d quad.

This work might be or not be relevant to https://github.com/bevyengine/bevy/issues/2724

<details>

<summary> ⚠️ Click for a video of the render ⚠️ I’ve been told it might hurt the eyes 👀 , maybe we should choose another effect just in case ?</summary>

https://user-images.githubusercontent.com/2290685/169138830-a6dc8a9f-8798-44b9-8d9e-449e60614916.mp4

</details>

# Request for feedbacks

- [ ] Is chromatic aberration effect ok ? (Correct term, not a danger for the eyes ?) I'm open to suggestion to make something different.
- [ ] Is the code idiomatic ? I preferred a "main camera -> **new camera with post processing applied to a quad**" approach to emulate minimum modification to existing code wanting to add global post processing.

---

## Changelog

- Add a full screen post processing shader example
2022-06-06 00:06:49 +00:00
Robert Swain
cc4062ec43 Split mesh shader files (#4867)
# Objective

- Split PBR and 2D mesh shaders into types and bindings to prepare the shaders to be more reusable.
- See #3969 for details. I'm doing this in multiple steps to make review easier.

---

## Changelog

- Changed: 2D and PBR mesh shaders are now split into types and bindings, the following shader imports are available: `bevy_pbr::mesh_view_types`, `bevy_pbr::mesh_view_bindings`, `bevy_pbr::mesh_types`, `bevy_pbr::mesh_bindings`, `bevy_sprite::mesh2d_view_types`, `bevy_sprite::mesh2d_view_bindings`, `bevy_sprite::mesh2d_types`, `bevy_sprite::mesh2d_bindings`

## Migration Guide

- In shaders for 3D meshes:
  - `#import bevy_pbr::mesh_view_bind_group` -> `#import bevy_pbr::mesh_view_bindings`
  - `#import bevy_pbr::mesh_struct` -> `#import bevy_pbr::mesh_types`
    - NOTE: If you are using the mesh bind group at bind group index 2, you can remove those binding statements in your shader and just use `#import bevy_pbr::mesh_bindings` which itself imports the mesh types needed for the bindings.
- In shaders for 2D meshes:
  - `#import bevy_sprite::mesh2d_view_bind_group` -> `#import bevy_sprite::mesh2d_view_bindings`
  - `#import bevy_sprite::mesh2d_struct` -> `#import bevy_sprite::mesh2d_types`
    - NOTE: If you are using the mesh2d bind group at bind group index 2, you can remove those binding statements in your shader and just use `#import bevy_sprite::mesh2d_bindings` which itself imports the mesh2d types needed for the bindings.
2022-05-31 23:23:25 +00:00
Aron Derenyi
2e8dfc02ef Fixing confusing near and far fields in Camera (#4457)
# Objective

- Fixes #4456 

## Solution

- Removed the `near` and `far` fields from the camera and the views.

---

## Changelog

- Removed the `near` and `far` fields from the camera and the views.
- Removed the `ClusterFarZMode::CameraFarPlane` far z mode.

## Migration Guide

- Cameras no longer accept near and far values during initialization
- `ClusterFarZMode::Constant` should be used with the far value instead of `ClusterFarZMode::CameraFarPlane`
2022-05-16 16:37:33 +00:00
bjorn3
d46cf69b7b Add the license for the FiraMono font (#3589)
I copied the license from https://github.com/mozilla/Fira/blob/master/LICENSE. The fact that the license file was missing came up in a discussion on [discord](https://discord.com/channels/691052431525675048/695741366520512563/929332683149017119).
2022-05-06 19:29:43 +00:00
Charles
6e5955f162 Add simple collision sound to breakout (#4331)
# Objective

- Add sound effect to the breakout example

## Solution

- Add a collision event and a system that listens to the event and plays a sound

I only added a single sound for all collisions for the sake of simplicity, but this could easily be extended to play a different sound depending on the type of entity hit.

The sound was generated randomly by using https://sfxr.me

https://sfxr.me/#11111GA9soYREjtsWhzjPrpMDEYSjX8Fo1E6PnKhxdw6tu869XW4EAc3nzpKVAYLMzToNcHQtQjeBqjZukqPmMDToGdYQQCWBnC3nEYfp53se5ep9btxRdLK

Closes #4326

https://user-images.githubusercontent.com/8348954/160154727-00e30743-3385-4c2f-97f0-1aaaf9a4dcc5.mp4

For some reason the video has a lot of delay in the sound, but when playing it locally there's no delay

---

## Changelog

- Added sound to breakout example
- Added bevy_audio and vorbis to the feature list ran for examples in CI

## Migration Guide

N/A
2022-04-14 20:20:38 +00:00
François
449a1d223c animation player (#4375)
# Objective

- Add a basic animation player
  - Single track
  - Not generic, can only animate `Transform`s
  - With plenty of possible optimisations available
  - Close-ish to https://github.com/bevyengine/rfcs/pull/49
- https://discord.com/channels/691052431525675048/774027865020039209/958820063148929064

## Solution

- Can play animations
  - looping or not
- Can pause animations
- Can seek in animation
- Can alter speed of animation
- I also removed the previous gltf animation example

https://user-images.githubusercontent.com/8672791/161051887-e79283f0-9803-448a-93d0-5f7a62acb02d.mp4
2022-04-02 22:36:02 +00:00
James Liu
31bd4ecbbc Mesh Skinning. Attempt #3 (#4238)
# Objective
Load skeletal weights and indices from GLTF files. Animate meshes.

## Solution
 - Load skeletal weights and indices from GLTF files.
 - Added `SkinnedMesh` component and ` SkinnedMeshInverseBindPose` asset
 - Added `extract_skinned_meshes` to extract joint matrices.
 - Added queue phase systems for enqueuing the buffer writes.

Some notes:

 -  This ports part of # #2359 to the current main.
 -  This generates new `BufferVec`s and bind groups every frame. The expectation here is that the number of `Query::get` calls during extract is probably going to be the stronger bottleneck, with up to 256 calls per skinned mesh. Until that is optimized, caching buffers and bind groups is probably a non-concern.
 - Unfortunately, due to the uniform size requirements, this means a 16KB buffer is allocated for every skinned mesh every frame. There's probably a few ways to get around this, but most of them require either compute shaders or storage buffers, which are both incompatible with WebGL2.

Co-authored-by: james7132 <contact@jamessliu.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: James Liu <contact@jamessliu.com>
2022-03-29 18:31:13 +00:00
François
fbe7a49d5b Gltf animations (#3751)
# Objective

- Load informations for animations from GLTF
- Make experimenting on animations easier

# Non Objective

- Implement a solutions for all animations in Bevy. This would need a discussion / RFC. The goal here is only to have the information available to try different APIs

## Solution

- Load animations with a representation close to the GLTF spec
- Add an example to display animations. There is an animation driver in the example, not in Bevy code, to show how it can be used. The example is cycling between examples from the official gltf sample ([AnimatedTriangle](https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/AnimatedTriangle), [BoxAnimated](https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/BoxAnimated)), and one from me with some cases not present in the official examples.


https://user-images.githubusercontent.com/8672791/150696656-073403f0-d921-43b6-beaf-099c7aee16ed.mp4




Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-03-22 02:26:34 +00:00
Jakob Hellermann
3ffa655cdd examples: add screenspace texture shader example (#4063)
Adds a new shader example showing how to sample a texture with screenspace coordinates, similar to the end [portal in minecraft](https://bugs.mojang.com/secure/attachment/163759/portal_frame_112.gif).

https://user-images.githubusercontent.com/22177966/156031195-33d14ed8-733f-4d9e-b1da-0fc807c994a5.mp4

I just used the already existent `models/FlightHelmet/FlightHelmet_Materials_LensesMat_OcclusionRoughMetal.png` texture but maybe we should use a dedicated texture for the example. Suggestions welcome.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-02-28 22:55:14 +00:00
Carter Anderson
44bf66e436 Minor Dark/Light Logo Tweak (#4051)
One more very minor tweak to the dark/light logo to make it render nicely on light themes (by using pure white for the outlines).
2022-02-27 02:09:42 +00:00
Carter Anderson
371c90f6fa Minor Bevy Logo Tweaks (#4050)
@BlackPhlox kindly pointed out and resolved a couple of inconsistencies in the bevy logo:
* The arc of the first bird's back had three vertices right next to each other, which created a noticeable sharp edge. This replaces them with a single vertex.
* The bottom part of the tail had a sharp edge, which was inconsistent with the top part of the tail. This was rounded out to mirror the top part.

I also took the chance to clean up some of the variants and (hopefully) improve the "bevy_logo_light_dark_and_dimmed" variant to improve how it renders on dark themes.
2022-02-27 01:38:17 +00:00
Carter Anderson
e369a8ad51 Mesh vertex buffer layouts (#3959)
This PR makes a number of changes to how meshes and vertex attributes are handled, which the goal of enabling easy and flexible custom vertex attributes:
* Reworks the `Mesh` type to use the newly added `VertexAttribute` internally
  * `VertexAttribute` defines the name, a unique `VertexAttributeId`, and a `VertexFormat`
  *  `VertexAttributeId` is used to produce consistent sort orders for vertex buffer generation, replacing the more expensive and often surprising "name based sorting"  
  * Meshes can be used to generate a `MeshVertexBufferLayout`, which defines the layout of the gpu buffer produced by the mesh. `MeshVertexBufferLayouts` can then be used to generate actual `VertexBufferLayouts` according to the requirements of a specific pipeline. This decoupling of "mesh layout" vs "pipeline vertex buffer layout" is what enables custom attributes. We don't need to standardize _mesh layouts_ or contort meshes to meet the needs of a specific pipeline. As long as the mesh has what the pipeline needs, it will work transparently. 
* Mesh-based pipelines now specialize on `&MeshVertexBufferLayout` via the new `SpecializedMeshPipeline` trait (which behaves like `SpecializedPipeline`, but adds `&MeshVertexBufferLayout`). The integrity of the pipeline cache is maintained because the `MeshVertexBufferLayout` is treated as part of the key (which is fully abstracted from implementers of the trait ... no need to add any additional info to the specialization key).    
* Hashing `MeshVertexBufferLayout` is too expensive to do for every entity, every frame. To make this scalable, I added a generalized "pre-hashing" solution to `bevy_utils`: `Hashed<T>` keys and `PreHashMap<K, V>` (which uses `Hashed<T>` internally) . Why didn't I just do the quick and dirty in-place "pre-compute hash and use that u64 as a key in a hashmap" that we've done in the past? Because its wrong! Hashes by themselves aren't enough because two different values can produce the same hash. Re-hashing a hash is even worse! I decided to build a generalized solution because this pattern has come up in the past and we've chosen to do the wrong thing. Now we can do the right thing! This did unfortunately require pulling in `hashbrown` and using that in `bevy_utils`, because avoiding re-hashes requires the `raw_entry_mut` api, which isn't stabilized yet (and may never be ... `entry_ref` has favor now, but also isn't available yet). If std's HashMap ever provides the tools we need, we can move back to that. Note that adding `hashbrown` doesn't increase our dependency count because it was already in our tree. I will probably break these changes out into their own PR.
* Specializing on `MeshVertexBufferLayout` has one non-obvious behavior: it can produce identical pipelines for two different MeshVertexBufferLayouts. To optimize the number of active pipelines / reduce re-binds while drawing, I de-duplicate pipelines post-specialization using the final `VertexBufferLayout` as the key.  For example, consider a pipeline that needs the layout `(position, normal)` and is specialized using two meshes: `(position, normal, uv)` and `(position, normal, other_vec2)`. If both of these meshes result in `(position, normal)` specializations, we can use the same pipeline! Now we do. Cool!

To briefly illustrate, this is what the relevant section of `MeshPipeline`'s specialization code looks like now:

```rust
impl SpecializedMeshPipeline for MeshPipeline {
    type Key = MeshPipelineKey;

    fn specialize(
        &self,
        key: Self::Key,
        layout: &MeshVertexBufferLayout,
    ) -> RenderPipelineDescriptor {
        let mut vertex_attributes = vec![
            Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
            Mesh::ATTRIBUTE_NORMAL.at_shader_location(1),
            Mesh::ATTRIBUTE_UV_0.at_shader_location(2),
        ];

        let mut shader_defs = Vec::new();
        if layout.contains(Mesh::ATTRIBUTE_TANGENT) {
            shader_defs.push(String::from("VERTEX_TANGENTS"));
            vertex_attributes.push(Mesh::ATTRIBUTE_TANGENT.at_shader_location(3));
        }

        let vertex_buffer_layout = layout
            .get_layout(&vertex_attributes)
            .expect("Mesh is missing a vertex attribute");
```

Notice that this is _much_ simpler than it was before. And now any mesh with any layout can be used with this pipeline, provided it has vertex postions, normals, and uvs. We even got to remove `HAS_TANGENTS` from MeshPipelineKey and `has_tangents` from `GpuMesh`, because that information is redundant with `MeshVertexBufferLayout`.

This is still a draft because I still need to:

* Add more docs
* Experiment with adding error handling to mesh pipeline specialization (which would print errors at runtime when a mesh is missing a vertex attribute required by a pipeline). If it doesn't tank perf, we'll keep it.
* Consider breaking out the PreHash / hashbrown changes into a separate PR.
* Add an example illustrating this change
* Verify that the "mesh-specialized pipeline de-duplication code" works properly

Please dont yell at me for not doing these things yet :) Just trying to get this in peoples' hands asap.

Alternative to #3120
Fixes #3030


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-02-23 23:21:13 +00:00