# Objective
My ecosystem crate, bevy_mod_outline, currently uses `SetMeshBindGroup`
as part of its custom rendering pipeline. I would like to allow for
possibility that, due to changes in 0.16, I need to customise the
behaviour of `SetMeshBindGroup` in order to make it work. However, not
all of the symbol needed to implement this render command are public
outside of Bevy.
## Solution
- Include `MorphIndices` in re-export list. I feel this is morally
equivalent to `SkinUniforms` already being exported.
- Change `MorphIndex::index` field to be public. I feel this is morally
equivalent to the `SkinByteOffset::byte_offset` field already being
public.
- Change `RenderMeshIntances::mesh_asset_id()` to be public (although
since all the fields of `RenderMeshInstances` are public it's possible
to work around this one by reimplementing).
These changes exclude:
- Making any change to the `RenderLightmaps` type as I don't need to
bind the light-maps for my use-case and I wanted to keep these changes
minimal. It has a private field which would need to be public or have
access methods.
- The changes already included in #18612.
## Testing
Confirmed that a copy of `SetMeshBindGroup` can be compiled outside of
Bevy with these changes, provided that the light-map code is removed.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
As of bevy 0.16-dev, the pre-existing public function
`bevy::pbr::setup_morph_and_skinning_defs()` is now passed a boolean
flag called `skins_use_uniform_buffers`. The value of this boolean is
computed by the function
`bevy_pbr::render::skin::skins_use_uniform_buffers()`, but it is not
exported publicly.
Found while porting
[bevy_mod_outline](https://github.com/komadori/bevy_mod_outline) to
0.16.
## Solution
Add `skin::skins_use_uniform_buffers` to the re-export list of
`bevy_pbr::render`.
## Testing
Confirmed test program can access public API.
Currently, Bevy rebuilds the buffer containing all the transforms for
joints every frame, during the extraction phase. This is inefficient in
cases in which many skins are present in the scene and their joints
don't move, such as the Caldera test scene.
To address this problem, this commit switches skin extraction to use a
set of retained GPU buffers with allocations managed by the offset
allocator. I use fine-grained change detection in order to determine
which skins need updating. Note that the granularity is on the level of
an entire skin, not individual joints. Using the change detection at
that level would yield poor performance in common cases in which an
entire skin is animated at once. Also, this patch yields additional
performance from the fact that changing joint transforms no longer
requires the skinned mesh to be re-extracted.
Note that this optimization can be a double-edged sword. In
`many_foxes`, fine-grained change detection regressed the performance of
`extract_skins` by 3.4x. This is because every joint is updated every
frame in that example, so change detection is pointless and is pure
overhead. Because the `many_foxes` workload is actually representative
of animated scenes, this patch includes a heuristic that disables
fine-grained change detection if the number of transformed entities in
the frame exceeds a certain fraction of the total number of joints.
Currently, this threshold is set to 25%. Note that this is a crude
heuristic, because it doesn't distinguish between the number of
transformed *joints* and the number of transformed *entities*; however,
it should be good enough to yield the optimum code path most of the
time.
Finally, this patch fixes a bug whereby skinned meshes are actually
being incorrectly retained if the buffer offsets of the joints of those
skinned meshes changes from frame to frame. To fix this without
retaining skins, we would have to re-extract every skinned mesh every
frame. Doing this was a significant regression on Caldera. With this PR,
by contrast, mesh joints stay at the same buffer offset, so we don't
have to update the `MeshInputUniform` containing the buffer offset every
frame. This also makes PR #17717 easier to implement, because that PR
uses the buffer offset from the previous frame, and the logic for
calculating that is simplified if the previous frame's buffer offset is
guaranteed to be identical to that of the current frame.
On Caldera, this patch reduces the time spent in `extract_skins` from
1.79 ms to near zero. On `many_foxes`, this patch regresses the
performance of `extract_skins` by approximately 10%-25%, depending on
the number of foxes. This has only a small impact on frame rate.
This commit makes skinned meshes batchable on platforms other than WebGL
2. On supported platforms, it replaces the two uniform buffers used for
joint matrices with a pair of storage buffers containing all matrices
for all skinned meshes packed together. The indices into the buffer are
stored in the mesh uniform and mesh input uniform. The GPU mesh
preprocessing step copies the indices in if that step is enabled.
On the `many_foxes` demo, I observed a frame time decrease from 15.470ms
to 11.935ms. This is the result of reducing the `submit_graph_commands`
time from an average of 5.45ms to 0.489ms, an 11x speedup in that
portion of rendering.

This is what the profile looks like for `many_foxes` after these
changes.

---------
Co-authored-by: François Mockers <mockersf@gmail.com>
This is a revamped equivalent to #9902, though it shares none of the
code. It handles all special cases that I've tested correctly.
The overall technique consists of double-buffering the joint matrix and
morph weights buffers, as most of the previous attempts to solve this
problem did. The process is generally straightforward. Note that, to
avoid regressing the ability of mesh extraction, skin extraction, and
morph target extraction to run in parallel, I had to add a new system to
rendering, `set_mesh_motion_vector_flags`. The comment there explains
the details; it generally runs very quickly.
I've tested this with modified versions of the `animated_fox`,
`morph_targets`, and `many_foxes` examples that add TAA, and the patch
works. To avoid bloating those examples, I didn't add switches for TAA
to them.
Addresses points (1) and (2) of #8423.
## Changelog
### Fixed
* Motion vectors, and therefore TAA, are now supported for meshes with
skins and/or morph targets.
Currently, `MeshUniform`s are rather large: 160 bytes. They're also
somewhat expensive to compute, because they involve taking the inverse
of a 3x4 matrix. Finally, if a mesh is present in multiple views, that
mesh will have a separate `MeshUniform` for each and every view, which
is wasteful.
This commit fixes these issues by introducing the concept of a *mesh
input uniform* and adding a *mesh uniform building* compute shader pass.
The `MeshInputUniform` is simply the minimum amount of data needed for
the GPU to compute the full `MeshUniform`. Most of this data is just the
transform and is therefore only 64 bytes. `MeshInputUniform`s are
computed during the *extraction* phase, much like skins are today, in
order to avoid needlessly copying transforms around on CPU. (In fact,
the render app has been changed to only store the translation of each
mesh; it no longer cares about any other part of the transform, which is
stored only on the GPU and the main world.) Before rendering, the
`build_mesh_uniforms` pass runs to expand the `MeshInputUniform`s to the
full `MeshUniform`.
The mesh uniform building pass does the following, all on GPU:
1. Copy the appropriate fields of the `MeshInputUniform` to the
`MeshUniform` slot. If a single mesh is present in multiple views, this
effectively duplicates it into each view.
2. Compute the inverse transpose of the model transform, used for
transforming normals.
3. If applicable, copy the mesh's transform from the previous frame for
TAA. To support this, we double-buffer the `MeshInputUniform`s over two
frames and swap the buffers each frame. The `MeshInputUniform`s for the
current frame contain the index of that mesh's `MeshInputUniform` for
the previous frame.
This commit produces wins in virtually every CPU part of the pipeline:
`extract_meshes`, `queue_material_meshes`,
`batch_and_prepare_render_phase`, and especially
`write_batched_instance_buffer` are all faster. Shrinking the amount of
CPU data that has to be shuffled around speeds up the entire rendering
process.
| Benchmark | This branch | `main` | Speedup |
|------------------------|-------------|---------|---------|
| `many_cubes -nfc` | 17.259 | 24.529 | 42.12% |
| `many_cubes -nfc -vpi` | 302.116 | 312.123 | 3.31% |
| `many_foxes` | 3.227 | 3.515 | 8.92% |
Because mesh uniform building requires compute shader, and WebGL 2 has
no compute shader, the existing CPU mesh uniform building code has been
left as-is. Many types now have both CPU mesh uniform building and GPU
mesh uniform building modes. Developers can opt into the old CPU mesh
uniform building by setting the `use_gpu_uniform_builder` option on
`PbrPlugin` to `false`.
Below are graphs of the CPU portions of `many-cubes
--no-frustum-culling`. Yellow is this branch, red is `main`.
`extract_meshes`:

It's notable that we get a small win even though we're now writing to a
GPU buffer.
`queue_material_meshes`:

There's a bit of a regression here; not sure what's causing it. In any
case it's very outweighed by the other gains.
`batch_and_prepare_render_phase`:

There's a huge win here, enough to make batching basically drop off the
profile.
`write_batched_instance_buffer`:

There's a massive improvement here, as expected. Note that a lot of it
simply comes from the fact that `MeshInputUniform` is `Pod`. (This isn't
a maintainability problem in my view because `MeshInputUniform` is so
simple: just 16 tightly-packed words.)
## Changelog
### Added
* Per-mesh instance data is now generated on GPU with a compute shader
instead of CPU, resulting in rendering performance improvements on
platforms where compute shaders are supported.
## Migration guide
* Custom render phases now need multiple systems beyond just
`batch_and_prepare_render_phase`. Code that was previously creating
custom render phases should now add a `BinnedRenderPhasePlugin` or
`SortedRenderPhasePlugin` as appropriate instead of directly adding
`batch_and_prepare_render_phase`.
# Objective
This PR aims to make it so that we don't accidentally go over
`MAX_TEXTURE_IMAGE_UNITS` (in WebGL) or
`maxSampledTexturesPerShaderStage` (in WebGPU), giving us some extra
leeway to add more view bind group textures.
(This PR is extracted from—and unblocks—#8015)
## Solution
- We replace the existing `view_layout` and `view_layout_multisampled`
pair with an array of 32 bind group layouts, generated ahead of time;
- For now, these layouts cover all the possible combinations of:
`multisampled`, `depth_prepass`, `normal_prepass`,
`motion_vector_prepass` and `deferred_prepass`:
- In the future, as @JMS55 pointed out, we can likely take out
`motion_vector_prepass` and `deferred_prepass`, as these are not really
needed for the mesh pipeline and can use separate pipelines. This would
bring the possible combinations down to 8;
- We can also add more "optional" textures as they become needed,
allowing the engine to scale to a wider variety of use cases in lower
end/web environments (e.g. some apps might just want normal and depth
prepasses, others might only want light probes), while still keeping a
high ceiling for high end native environments where more textures are
supported.
- While preallocating bind group layouts is relatively cheap, the number
of combinations grows exponentially, so we should likely limit ourselves
to something like at most 256–1024 total layouts until we find a better
solution (like generating them lazily)
- To make this mechanism a little bit more explicit/discoverable, so
that compatibility with WebGPU/WebGL is not broken by accident, we add a
`MESH_PIPELINE_VIEW_LAYOUT_SAFE_MAX_TEXTURES` const and warn whenever
the number of textures in the layout crosses it.
- The warning is gated by `#[cfg(debug_assertions)]` and not issued in
release builds;
- We're counting the actual textures in the bind group layout instead of
using some roundabout metric so it should be accurate;
- Right now `MESH_PIPELINE_VIEW_LAYOUT_SAFE_MAX_TEXTURES` is set to 10
in order to leave 6 textures free for other groups;
- Currently there's no combination that would cause us to go over the
limit, but that will change once #8015 lands.
---
## Changelog
- `MeshPipeline` view bind group layouts now vary based on the current
multisampling and prepass states, saving a couple of texture binding
entries when prepasses are not in use.
## Migration Guide
- `MeshPipeline::view_layout` and
`MeshPipeline::view_layout_multisampled` have been replaced with a
private array to accomodate for variable view bind group layouts. To
obtain a view bind group layout for the current pipeline state, use the
new `MeshPipeline::get_view_layout()` or
`MeshPipeline::get_view_layout_from_key()` methods.
# Objective
mesh.rs is infamously large. We could split off unrelated code.
## Solution
Morph targets are very similar to skinning and have their own module. We
move skinned meshes to an independent module like morph targets and give
the systems similar names.
### Open questions
Should the skinning systems and structs stay public?
---
## Migration Guide
Renamed skinning systems, resources and components:
- extract_skinned_meshes -> extract_skins
- prepare_skinned_meshes -> prepare_skins
- SkinnedMeshUniform -> SkinUniform
- SkinnedMeshJoints -> SkinIndex
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
# Objective
- Add morph targets to `bevy_pbr` (closes#5756) & load them from glTF
- Supersedes #3722
- Fixes#6814
[Morph targets][1] (also known as shape interpolation, shape keys, or
blend shapes) allow animating individual vertices with fine grained
controls. This is typically used for facial expressions. By specifying
multiple poses as vertex offset, and providing a set of weight of each
pose, it is possible to define surprisingly realistic transitions
between poses. Blending between multiple poses also allow composition.
Morph targets are part of the [gltf standard][2] and are a feature of
Unity and Unreal, and babylone.js, it is only natural to implement them
in bevy.
## Solution
This implementation of morph targets uses a 3d texture where each pixel
is a component of an animated attribute. Each layer is a different
target. We use a 2d texture for each target, because the number of
attribute×components×animated vertices is expected to always exceed the
maximum pixel row size limit of webGL2. It copies fairly closely the way
skinning is implemented on the CPU side, while on the GPU side, the
shader morph target implementation is a relatively trivial detail.
We add an optional `morph_texture` to the `Mesh` struct. The
`morph_texture` is built through a method that accepts an iterator over
attribute buffers.
The `MorphWeights` component, user-accessible, controls the blend of
poses used by mesh instances (so that multiple copy of the same mesh may
have different weights), all the weights are uploaded to a uniform
buffer of 256 `f32`. We limit to 16 poses per mesh, and a total of 256
poses.
More literature:
* Old babylone.js implementation (vertex attribute-based):
https://www.eternalcoding.com/dev-log-1-morph-targets/
* Babylone.js implementation (similar to ours):
https://www.youtube.com/watch?v=LBPRmGgU0PE
* GPU gems 3:
https://developer.nvidia.com/gpugems/gpugems3/part-i-geometry/chapter-3-directx-10-blend-shapes-breaking-limits
* Development discord thread
https://discord.com/channels/691052431525675048/1083325980615114772https://user-images.githubusercontent.com/26321040/231181046-3bca2ab2-d4d9-472e-8098-639f1871ce2e.mp4https://github.com/bevyengine/bevy/assets/26321040/d2a0c544-0ef8-45cf-9f99-8c3792f5a258
## Acknowledgements
* Thanks to `storytold` for sponsoring the feature
* Thanks to `superdump` and `james7132` for guidance and help figuring
out stuff
## Future work
- Handling of less and more attributes (eg: animated uv, animated
arbitrary attributes)
- Dynamic pose allocation (so that zero-weighted poses aren't uploaded
to GPU for example, enables much more total poses)
- Better animation API, see #8357
----
## Changelog
- Add morph targets to bevy meshes
- Support up to 64 poses per mesh of individually up to 116508 vertices,
animation currently strictly limited to the position, normal and tangent
attributes.
- Load a morph target using `Mesh::set_morph_targets`
- Add `VisitMorphTargets` and `VisitMorphAttributes` traits to
`bevy_render`, this allows defining morph targets (a fairly complex and
nested data structure) through iterators (ie: single copy instead of
passing around buffers), see documentation of those traits for details
- Add `MorphWeights` component exported by `bevy_render`
- `MorphWeights` control mesh's morph target weights, blending between
various poses defined as morph targets.
- `MorphWeights` are directly inherited by direct children (single level
of hierarchy) of an entity. This allows controlling several mesh
primitives through a unique entity _as per GLTF spec_.
- Add `MorphTargetNames` component, naming each indices of loaded morph
targets.
- Load morph targets weights and buffers in `bevy_gltf`
- handle morph targets animations in `bevy_animation` (previously, it
was a `warn!` log)
- Add the `MorphStressTest.gltf` asset for morph targets testing, taken
from the glTF samples repo, CC0.
- Add morph target manipulation to `scene_viewer`
- Separate the animation code in `scene_viewer` from the rest of the
code, reducing `#[cfg(feature)]` noise
- Add the `morph_targets.rs` example to show off how to manipulate morph
targets, loading `MorpStressTest.gltf`
## Migration Guide
- (very specialized, unlikely to be touched by 3rd parties)
- `MeshPipeline` now has a single `mesh_layouts` field rather than
separate `mesh_layout` and `skinned_mesh_layout` fields. You should
handle all possible mesh bind group layouts in your implementation
- You should also handle properly the new `MORPH_TARGETS` shader def and
mesh pipeline key. A new function is exposed to make this easier:
`setup_moprh_and_skinning_defs`
- The `MeshBindGroup` is now `MeshBindGroups`, cached bind groups are
now accessed through the `get` method.
[1]: https://en.wikipedia.org/wiki/Morph_target_animation
[2]:
https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#morph-targets
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
<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;
This adds "high level" `Material` and `SpecializedMaterial` traits, which can be used with a `MaterialPlugin<T: SpecializedMaterial>`. `MaterialPlugin` automatically registers the appropriate resources, draw functions, and queue systems. The `Material` trait is simpler, and should cover most use cases. `SpecializedMaterial` is like `Material`, but it also requires defining a "specialization key" (see #3031). `Material` has a trivial blanket impl of `SpecializedMaterial`, which allows us to use the same types + functions for both.
This makes defining custom 3d materials much simpler (see the `shader_material` example diff) and ensures consistent behavior across all 3d materials (both built in and custom). I ported the built in `StandardMaterial` to `MaterialPlugin`. There is also a new `MaterialMeshBundle<T: SpecializedMaterial>`, which `PbrBundle` aliases to.
# Objective
- Our crevice is still called "crevice", which we can't use for a release
- Users would need to use our "crevice" directly to be able to use the derive macro
## Solution
- Rename crevice to bevy_crevice, and crevice-derive to bevy-crevice-derive
- Re-export it from bevy_render, and use it from bevy_render everywhere
- Fix derive macro to work either from bevy_render, from bevy_crevice, or from bevy
## Remaining
- It is currently re-exported as `bevy::render::bevy_crevice`, is it the path we want?
- After a brief suggestion to Cart, I changed the version to follow Bevy version instead of crevice, do we want that?
- Crevice README.md need to be updated
- in the `Cargo.toml`, there are a few things to change. How do we want to change them? How do we keep attributions to original Crevice?
```
authors = ["Lucien Greathouse <me@lpghatguy.com>"]
documentation = "https://docs.rs/crevice"
homepage = "https://github.com/LPGhatguy/crevice"
repository = "https://github.com/LPGhatguy/crevice"
```
Co-authored-by: François <8672791+mockersf@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes#3352Fixes#3208
## Solution
- Update wgpu to 0.12
- Update naga to 0.8
- Resolve compilation errors
- Remove [[block]] from WGSL shaders (because it is depracated and now wgpu cant parse it)
- Replace `elseif` with `else if` in pbr.wgsl
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.
The examples are all ported over and operational with a few exceptions:
* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.