Commit graph

649 commits

Author SHA1 Message Date
Patrick Walton
9da0b2a0ec
Make render phases render world resources instead of components. (#13277)
This commit makes us stop using the render world ECS for
`BinnedRenderPhase` and `SortedRenderPhase` and instead use resources
with `EntityHashMap`s inside. There are three reasons to do this:

1. We can use `clear()` to clear out the render phase collections
instead of recreating the components from scratch, allowing us to reuse
allocations.

2. This is a prerequisite for retained bins, because components can't be
retained from frame to frame in the render world, but resources can.

3. We want to move away from storing anything in components in the
render world ECS, and this is a step in that direction.

This patch results in a small performance benefit, due to point (1)
above.

## Changelog

### Changed

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources.

## Migration Guide

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources. Instead of querying for the
components, look the camera entity up in the
`ViewBinnedRenderPhases`/`ViewSortedRenderPhases` tables.
2024-05-21 18:23:04 +00:00
IceSentry
bf2aced279
Remove another .view_layouts (#13410)
I forgot to save that file when submitting #13394 😅
2024-05-19 00:08:27 +00:00
Patrick Walton
846757cb38
Make the prepass shader compile when lightmaps are present. (#13402)
Commit 3f5a090b1b added a reference to
`STANDARD_MATERIAL_FLAGS_BASE_COLOR_UV_BIT`, a nonexistent identifier,
in the alpha discard portion of the prepass shader. Moreover, the logic
didn't make sense to me. I think the code was trying to choose between
the two UV sets depending on which is present, so I made it do that.

I noticed this when trying Bistro with #13277. I'm not sure why this
issue didn't manifest itself before, but it's clearly a bug, so here's a
fix. We should probably merge this before 0.14.
2024-05-18 22:28:31 +00:00
Johannes Hackel
1fcf6a444f
Add emissive_exposure_weight to the StandardMaterial (#13350)
# Objective

- The emissive color gets multiplied by the camera exposure value. But
this cancels out almost any emissive effect.
- Fixes #13133
- Closes PR #13337 

## Solution
- Add emissive_exposure_weight to the StandardMaterial
- In the shader this value is stored in the alpha channel of the
emissive color.
- This value defines how much the exposure influences the emissive
color.
- It's equal to Google's Filament:
https://google.github.io/filament/Materials.html#emissive

4f021583f1/shaders/src/shading_lit.fs (L287)

## Testing

- The result of
[EmissiveStrengthTest](https://github.com/KhronosGroup/glTF-Sample-Models/tree/main/2.0/EmissiveStrengthTest)
with the default value of 0.0:

without bloom:

![emissive_fix](https://github.com/bevyengine/bevy/assets/688816/8f8c131a-464a-4d7b-a9e4-4e28d679ee5d)

with bloom:

![emissive_fix_bloom](https://github.com/bevyengine/bevy/assets/688816/89f200ee-3bd5-4daa-bf64-8999b56df3fa)
2024-05-17 13:49:53 +00:00
IceSentry
aa907d5437
Remove unnecessary .view_layouts (#13394)
# Objective

- The volumetric fog PR originally needed to be modified to use
`.view_layouts` but that was changed in another PR. The merge with main
still kept those around.

## Solution

- Remove them because they aren't necessary
2024-05-16 19:12:36 +00:00
Patrick Walton
19bfa41768
Implement volumetric fog and volumetric lighting, also known as light shafts or god rays. (#13057)
This commit implements a more physically-accurate, but slower, form of
fog than the `bevy_pbr::fog` module does. Notably, this *volumetric fog*
allows for light beams from directional lights to shine through,
creating what is known as *light shafts* or *god rays*.

To add volumetric fog to a scene, add `VolumetricFogSettings` to the
camera, and add `VolumetricLight` to directional lights that you wish to
be volumetric. `VolumetricFogSettings` has numerous settings that allow
you to define the accuracy of the simulation, as well as the look of the
fog. Currently, only interaction with directional lights that have
shadow maps is supported. Note that the overhead of the effect scales
directly with the number of directional lights in use, so apply
`VolumetricLight` sparingly for the best results.

The overall algorithm, which is implemented as a postprocessing effect,
is a combination of the techniques described in [Scratchapixel] and
[this blog post]. It uses raymarching in screen space, transformed into
shadow map space for sampling and combined with physically-based
modeling of absorption and scattering. Bevy employs the widely-used
[Henyey-Greenstein phase function] to model asymmetry; this essentially
allows light shafts to fade into and out of existence as the user views
them.

Volumetric rendering is a huge subject, and I deliberately kept the
scope of this commit small. Possible follow-ups include:

1. Raymarching at a lower resolution.

2. A post-processing blur (especially useful when combined with (1)).

3. Supporting point lights and spot lights.

4. Supporting lights with no shadow maps.

5. Supporting irradiance volumes and reflection probes.

6. Voxel components that reuse the volumetric fog code to create voxel
shapes.

7. *Horizon: Zero Dawn*-style clouds.

These are all useful, but out of scope of this patch for now, to keep
things tidy and easy to review.

A new example, `volumetric_fog`, has been added to demonstrate the
effect.

## Changelog

### Added

* A new component, `VolumetricFog`, is available, to allow for a more
physically-accurate, but more resource-intensive, form of fog.

* A new component, `VolumetricLight`, can be placed on directional
lights to make them interact with `VolumetricFog`. Notably, this allows
such lights to emit light shafts/god rays.

![Screenshot 2024-04-21
162808](https://github.com/bevyengine/bevy/assets/157897/7a1fc81d-eed5-4735-9419-286c496391a9)

![Screenshot 2024-04-21
132005](https://github.com/bevyengine/bevy/assets/157897/e6d3b5ca-8f59-488d-a3de-15e95aaf4995)

[Scratchapixel]:
https://www.scratchapixel.com/lessons/3d-basic-rendering/volume-rendering-for-developers/intro-volume-rendering.html

[this blog post]: https://www.alexandre-pestana.com/volumetric-lights/

[Henyey-Greenstein phase function]:
https://www.pbr-book.org/4ed/Volume_Scattering/Phase_Functions#TheHenyeyndashGreensteinPhaseFunction
2024-05-16 17:13:18 +00:00
charlotte
4c3b7679ec
#12502 Remove limit on RenderLayers. (#13317)
# Objective

Remove the limit of `RenderLayer` by using a growable mask using
`SmallVec`.

Changes adopted from @UkoeHB's initial PR here
https://github.com/bevyengine/bevy/pull/12502 that contained additional
changes related to propagating render layers.

Changes

## Solution

The main thing needed to unblock this is removing `RenderLayers` from
our shader code. This primarily affects `DirectionalLight`. We are now
computing a `skip` field on the CPU that is then used to skip the light
in the shader.

## Testing

Checked a variety of examples and did a quick benchmark on `many_cubes`.
There were some existing problems identified during the development of
the original pr (see:
https://discord.com/channels/691052431525675048/1220477928605749340/1221190112939872347).
This PR shouldn't change any existing behavior besides removing the
layer limit (sans the comment in migration about `all` layers no longer
being possible).

---

## Changelog

Removed the limit on `RenderLayers` by using a growable bitset that only
allocates when layers greater than 64 are used.

## Migration Guide

- `RenderLayers::all()` no longer exists. Entities expecting to be
visible on all layers, e.g. lights, should compute the active layers
that are in use.

---------

Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
2024-05-16 16:15:47 +00:00
Johannes Hackel
1efa578ffb
Fix transmission by setting the correct value for transmissive_lighting_input.F_ab (#13379)
# Objective

- The clearcoat PR #13031 had a small typo which broke transmission
- Fixes #13284

## Solution

- Set transmissive_lighting_input.F_ab to the correct value


![transmission_fix](https://github.com/bevyengine/bevy/assets/688816/92158117-de3a-4fa5-8af8-dcbd1d5eee04)
2024-05-16 14:33:32 +00:00
Xzihnago
eba8744a70
Add Debug derive for ScreenSpaceAmbientOcclusionSettings struct (#13387)
# Objective

To streamline the code which utilizes `Debug` in user's struct like
`GraphicsSettings`. This addition aims to enhance code simplicity and
readability.

## Solution

Add `Debug` derive for `ScreenSpaceAmbientOcclusionSettings` struct.

## Testing

Should have no impact.
2024-05-16 11:29:34 +00:00
Csányi István
f91fd322b7
Skip redundant mesh_position_local_to_world call in vertex prepass shader (#13158)
# Objective

Optimize vertex prepass shader maybe?
Make it consistent with the base vertex shader

## Solution

`mesh_position_local_to_clip` just calls `mesh_position_local_to_world`
and then `position_world_to_clip`
since `out.world_position` is getting calculated anyway a few lines
below, just move it up and use it's output to calculate `out.position`.

It is the same as in the base vertex shader (`mesh.wgsl`).

Note: I have no idea if there is a reason that it was this way. I'm not
an expert, just noticed this inconsistency while messing with custom
shaders.
2024-05-14 16:31:58 +00:00
Griffin
519ed5de42
Apply uv transform in the prepass (#13250)
# Objective

- The UV transform was applied in the main pass but not the prepass.

## Solution

- Apply the UV transform in the prepass.

## Testing

- The normals in my scene now look correct when using the prepass.
2024-05-13 22:33:09 +00:00
JoshValjosh
2037b880ac
Add docs for PointLight (#13355)
Fixes #13106
2024-05-13 18:55:36 +00:00
Johannes Hackel
3f5a090b1b
Add UV channel selection to StandardMaterial (#13200)
# Objective

- The StandardMaterial always uses ATTRIBUTE_UV_0 for each texture
except lightmap. This is not flexible enough for a lot of gltf Files.
- Fixes #12496
- Fixes #13086
- Fixes #13122
- Closes #13153

## Solution

- The StandardMaterial gets extended for each texture by an UvChannel
enum. It defaults to Uv0 but can also be set to Uv1.
- The gltf loader now handles the texcoord information. If the texcoord
is not supported it creates a warning.
- It uses StandardMaterial shader defs to define which attribute to use.

## Testing

This fixes #12496 for example:

![wall_fixed](https://github.com/bevyengine/bevy/assets/688816/bc37c9e1-72ba-4e59-b092-5ee10dade603)

For testing of all kind of textures I used the TextureTransformMultiTest
from
https://github.com/KhronosGroup/glTF-Sample-Assets/tree/main/Models/TextureTransformMultiTest
Its purpose is to test multiple texture transfroms but it is also a good
test for different texcoords.
It also shows the issue with emission #13133.

Before:

![TextureTransformMultiTest_main](https://github.com/bevyengine/bevy/assets/688816/aa701d04-5a3f-4df1-a65f-fc770ab6f4ab)

After:

![TextureTransformMultiTest_texcoord](https://github.com/bevyengine/bevy/assets/688816/c3f91943-b830-4068-990f-e4f2c97771ee)
2024-05-13 18:23:09 +00:00
François Mockers
173db7726f
remove unused warnings in release (#13344)
# Objective

- When building for release, there are "unused" warnings:
```
warning: unused import: `bevy_utils::warn_once`
  --> crates/bevy_pbr/src/render/mesh_view_bindings.rs:32:5
   |
32 | use bevy_utils::warn_once;
   |     ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(unused_imports)]` on by default

warning: unused variable: `texture_count`
   --> crates/bevy_pbr/src/render/mesh_view_bindings.rs:371:17
    |
371 |             let texture_count: usize = entries
    |                 ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_texture_count`
    |
    = note: `#[warn(unused_variables)]` on by default
```

## Solution

- Gate the import and definition by the same cfg as their uses
2024-05-12 22:30:34 +00:00
moonlightaria
3f2cc244d7
Add color conversions #13224 (#13276)
# Objective
fixes #13224
adds conversions for Vec3 and Vec4 since these appear so often

## Solution
added Covert trait (couldn't think of good name) for [f32; 4], [f32, 3],
Vec4, and Vec3 along with the symmetric implementation

## Changelog
added conversions between arrays and vector to colors and vice versa

#migration
LinearRgba appears to have already had implicit conversions for [f32;4]
and Vec4
2024-05-09 18:01:52 +00:00
Patrick Walton
0dddfa07ab
Fix the WebGL 2 backend by giving the visibility_ranges array a fixed length. (#13210)
WebGL 2 doesn't support variable-length uniform buffer arrays. So we
arbitrarily set the length of the visibility ranges field to 64 on that
platform.

---------

Co-authored-by: IceSentry <c.giguere42@gmail.com>
2024-05-08 07:34:59 +00:00
IceSentry
4737106bdd
Extract mesh view layouts logic (#13266)
Copied almost verbatim from the volumetric fog PR

# Objective

- Managing mesh view layouts is complicated

## Solution

- Extract it to it's own struct
- This was done as part of #13057 and is copied almost verbatim. I
wanted to keep this part of the PR it's own atomic commit in case we
ever have to revert fog or run a bisect. This change is good whether or
not we have volumetric fog.

Co-Authored-By: @pcwalton
2024-05-07 06:46:41 +00:00
Fpgu
60a73fa60b
Use Dir3 for local axis methods in GlobalTransform (#13264)
Switched the return type from `Vec3` to `Dir3` for directional axis
methods within the `GlobalTransform` component.

## Migration Guide
The `GlobalTransform` component's directional axis methods (e.g.,
`right()`, `left()`, `up()`, `down()`, `back()`, `forward()`) have been
updated from returning `Vec3` to `Dir3`.
2024-05-06 20:52:05 +00:00
Patrick Walton
59b52fc94e
Modulate the emissive texture by the emissive color again. (#13251)
Fixes a regression introduced by #13031.
2024-05-06 20:06:10 +00:00
Patrick Walton
77ed72bc16
Implement clearcoat per the Filament and the KHR_materials_clearcoat specifications. (#13031)
Clearcoat is a separate material layer that represents a thin
translucent layer of a material. Examples include (from the [Filament
spec]) car paint, soda cans, and lacquered wood. This commit implements
support for clearcoat following the Filament and Khronos specifications,
marking the beginnings of support for multiple PBR layers in Bevy.

The [`KHR_materials_clearcoat`] specification describes the clearcoat
support in glTF. In Blender, applying a clearcoat to the Principled BSDF
node causes the clearcoat settings to be exported via this extension. As
of this commit, Bevy parses and reads the extension data when present in
glTF. Note that the `gltf` crate has no support for
`KHR_materials_clearcoat`; this patch therefore implements the JSON
semantics manually.

Clearcoat is integrated with `StandardMaterial`, but the code is behind
a series of `#ifdef`s that only activate when clearcoat is present.
Additionally, the `pbr_feature_layer_material_textures` Cargo feature
must be active in order to enable support for clearcoat factor maps,
clearcoat roughness maps, and clearcoat normal maps. This approach
mirrors the same pattern used by the existing transmission feature and
exists to avoid running out of texture bindings on platforms like WebGL
and WebGPU. Note that constant clearcoat factors and roughness values
*are* supported in the browser; only the relatively-less-common maps are
disabled on those platforms.

This patch refactors the lighting code in `StandardMaterial`
significantly in order to better support multiple layers in a natural
way. That code was due for a refactor in any case, so this is a nice
improvement.

A new demo, `clearcoat`, has been added. It's based on [the
corresponding three.js demo], but all the assets (aside from the skybox
and environment map) are my original work.

[Filament spec]:
https://google.github.io/filament/Filament.html#materialsystem/clearcoatmodel

[`KHR_materials_clearcoat`]:
https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md

[the corresponding three.js demo]:
https://threejs.org/examples/webgl_materials_physical_clearcoat.html

![Screenshot 2024-04-19
101143](https://github.com/bevyengine/bevy/assets/157897/3444bcb5-5c20-490c-b0ad-53759bd47ae2)

![Screenshot 2024-04-19
102054](https://github.com/bevyengine/bevy/assets/157897/6e953944-75b8-49ef-bc71-97b0a53b3a27)

## Changelog

### Added

* `StandardMaterial` now supports a clearcoat layer, which represents a
thin translucent layer over an underlying material.
* The glTF loader now supports the `KHR_materials_clearcoat` extension,
representing materials with clearcoat layers.

## Migration Guide

* The lighting functions in the `pbr_lighting` WGSL module now have
clearcoat parameters, if `STANDARD_MATERIAL_CLEARCOAT` is defined.

* The `R` reflection vector parameter has been removed from some
lighting functions, as it was unused.
2024-05-05 22:57:05 +00:00
JMS55
77ebabc4fe
Meshlet remove per-cluster data upload (#13125)
# Objective

- Per-cluster (instance of a meshlet) data upload is ridiculously
expensive in both CPU and GPU time (8 bytes per cluster, millions of
clusters, you very quickly run into PCIE bandwidth maximums, and lots of
CPU-side copies and malloc).
- We need to be uploading only per-instance/entity data. Anything else
needs to be done on the GPU.

## Solution

- Per instance, upload:
- `meshlet_instance_meshlet_counts_prefix_sum` - An exclusive prefix sum
over the count of how many clusters each instance has.
- `meshlet_instance_meshlet_slice_starts` - The starting index of the
meshlets for each instance within the `meshlets` buffer.
- A new `fill_cluster_buffers` pass once at the start of the frame has a
thread per cluster, and finds its instance ID and meshlet ID via a
binary search of `meshlet_instance_meshlet_counts_prefix_sum` to find
what instance it belongs to, and then uses that plus
`meshlet_instance_meshlet_slice_starts` to find what number meshlet
within the instance it is. The shader then writes out the per-cluster
instance/meshlet ID buffers for later passes to quickly read from.
- I've gone from 45 -> 180 FPS in my stress test scene, and saved
~30ms/frame of overall CPU/GPU time.
2024-05-04 19:56:19 +00:00
arcashka
6027890a11
move wgsl color operations from bevy_pbr to bevy_render (#13209)
# Objective

`bevy_pbr/utils.wgsl` shader file contains mathematical constants and
color conversion functions. Both of those should be accessible without
enabling `bevy_pbr` feature. For example, tonemapping can be done in non
pbr scenario, and it uses color conversion functions.

Fixes #13207

## Solution

* Move mathematical constants (such as PI, E) from
`bevy_pbr/src/render/utils.wgsl` into `bevy_render/src/maths.wgsl`
* Move color conversion functions from `bevy_pbr/src/render/utils.wgsl`
into new file `bevy_render/src/color_operations.wgsl`

## Testing
Ran multiple examples, checked they are working:
* tonemapping
* color_grading
* 3d_scene
* animated_material
* deferred_rendering
* 3d_shapes
* fog
* irradiance_volumes
* meshlet
* parallax_mapping
* pbr
* reflection_probes
* shadow_biases
* 2d_gizmos
* light_gizmos
---

## Changelog
* Moved mathematical constants (such as PI, E) from
`bevy_pbr/src/render/utils.wgsl` into `bevy_render/src/maths.wgsl`
* Moved color conversion functions from `bevy_pbr/src/render/utils.wgsl`
into new file `bevy_render/src/color_operations.wgsl`

## Migration Guide
In user's shader code replace usage of mathematical constants from
`bevy_pbr::utils` to the usage of the same constants from
`bevy_render::maths`.
2024-05-04 10:30:23 +00:00
Kristoffer Søholm
2089a28717
Add BufferVec, an higher-performance alternative to StorageBuffer, and make GpuArrayBuffer use it. (#13199)
This is an adoption of #12670 plus some documentation fixes. See that PR
for more details.

---

## Changelog

* Renamed `BufferVec` to `RawBufferVec` and added a new `BufferVec`
type.

## Migration Guide
`BufferVec` has been renamed to `RawBufferVec` and a new similar type
has taken the `BufferVec` name.

---------

Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
2024-05-03 11:39:21 +00:00
Patrick Walton
31835ff76d
Implement visibility ranges, also known as hierarchical levels of detail (HLODs). (#12916)
Implement visibility ranges, also known as hierarchical levels of detail
(HLODs).

This commit introduces a new component, `VisibilityRange`, which allows
developers to specify camera distances in which meshes are to be shown
and hidden. Hiding meshes happens early in the rendering pipeline, so
this feature can be used for level of detail optimization. Additionally,
this feature is properly evaluated per-view, so different views can show
different levels of detail.

This feature differs from proper mesh LODs, which can be implemented
later. Engines generally implement true mesh LODs later in the pipeline;
they're typically more efficient than HLODs with GPU-driven rendering.
However, mesh LODs are more limited than HLODs, because they require the
lower levels of detail to be meshes with the same vertex layout and
shader (and perhaps the same material) as the original mesh. Games often
want to use objects other than meshes to replace distant models, such as
*octahedral imposters* or *billboard imposters*.

The reason why the feature is called *hierarchical level of detail* is
that HLODs can replace multiple meshes with a single mesh when the
camera is far away. This can be useful for reducing drawcall count. Note
that `VisibilityRange` doesn't automatically propagate down to children;
it must be placed on every mesh.

Crossfading between different levels of detail is supported, using the
standard 4x4 ordered dithering pattern from [1]. The shader code to
compute the dithering patterns should be well-optimized. The dithering
code is only active when visibility ranges are in use for the mesh in
question, so that we don't lose early Z.

Cascaded shadow maps show the HLOD level of the view they're associated
with. Point light and spot light shadow maps, which have no CSMs,
display all HLOD levels that are visible in any view. To support this
efficiently and avoid doing visibility checks multiple times, we
precalculate all visible HLOD levels for each entity with a
`VisibilityRange` during the `check_visibility_range` system.

A new example, `visibility_range`, has been added to the tree, as well
as a new low-poly version of the flight helmet model to go with it. It
demonstrates use of the visibility range feature to provide levels of
detail.

[1]: https://en.wikipedia.org/wiki/Ordered_dithering#Threshold_map

[^1]: Unreal doesn't have a feature that exactly corresponds to
visibility ranges, but Unreal's HLOD system serves roughly the same
purpose.

## Changelog

### Added

* A new `VisibilityRange` component is available to conditionally enable
entity visibility at camera distances, with optional crossfade support.
This can be used to implement different levels of detail (LODs).

## Screenshots

High-poly model:
![Screenshot 2024-04-09
185541](https://github.com/bevyengine/bevy/assets/157897/7e8be017-7187-4471-8866-974e2d8f2623)

Low-poly model up close:
![Screenshot 2024-04-09
185546](https://github.com/bevyengine/bevy/assets/157897/429603fe-6bb7-4246-8b4e-b4888fd1d3a0)

Crossfading between the two:
![Screenshot 2024-04-09
185604](https://github.com/bevyengine/bevy/assets/157897/86d0d543-f8f3-49ec-8fe5-caa4d0784fd4)

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-05-03 00:11:35 +00:00
BD103
e357b63448
Add README.md to all crates (#13184)
# Objective

- `README.md` is a common file that usually gives an overview of the
folder it is in.
- When on <https://crates.io>, `README.md` is rendered as the main
description.
- Many crates in this repository are lacking `README.md` files, which
makes it more difficult to understand their purpose.

<img width="1552" alt="image"
src="https://github.com/bevyengine/bevy/assets/59022059/78ebf91d-b0c4-4b18-9874-365d6310640f">

- There are also a few inconsistencies with `README.md` files that this
PR and its follow-ups intend to fix.

## Solution

- Create a `README.md` file for all crates that do not have one.
- This file only contains the title of the crate (underscores removed,
proper capitalization, acronyms expanded) and the <https://shields.io>
badges.
- Remove the `readme` field in `Cargo.toml` for `bevy` and
`bevy_reflect`.
- This field is redundant because [Cargo automatically detects
`README.md`
files](https://doc.rust-lang.org/cargo/reference/manifest.html#the-readme-field).
The field is only there if you name it something else, like `INFO.md`.
- Fix capitalization of `bevy_utils`'s `README.md`.
- It was originally `Readme.md`, which is inconsistent with the rest of
the project.
- I created two commits renaming it to `README.md`, because Git appears
to be case-insensitive.
- Expand acronyms in title of `bevy_ptr` and `bevy_utils`.
- In the commit where I created all the new `README.md` files, I
preferred using expanded acronyms in the titles. (E.g. "Bevy Developer
Tools" instead of "Bevy Dev Tools".)
- This commit changes the title of existing `README.md` files to follow
the same scheme.
- I do not feel strongly about this change, please comment if you
disagree and I can revert it.
- Add <https://shields.io> badges to `bevy_time` and `bevy_transform`,
which are the only crates currently lacking them.

---

## Changelog

- Added `README.md` files to all crates missing it.
2024-05-02 18:56:00 +00:00
Patrick Walton
961b24deaf
Implement filmic color grading. (#13121)
This commit expands Bevy's existing tonemapping feature to a complete
set of filmic color grading tools, matching those of engines like Unity,
Unreal, and Godot. The following features are supported:

* White point adjustment. This is inspired by Unity's implementation of
the feature, but simplified and optimized. *Temperature* and *tint*
control the adjustments to the *x* and *y* chromaticity values of [CIE
1931]. Following Unity, the adjustments are made relative to the [D65
standard illuminant] in the [LMS color space].

* Hue rotation. This simply converts the RGB value to [HSV], alters the
hue, and converts back.

* Color correction. This allows the *gamma*, *gain*, and *lift* values
to be adjusted according to the standard [ASC CDL combined function].

* Separate color correction for shadows, midtones, and highlights.
Blender's source code was used as a reference for the implementation of
this. The midtone ranges can be adjusted by the user. To avoid abrupt
color changes, a small crossfade is used between the different sections
of the image, again following Blender's formulas.

A new example, `color_grading`, has been added, offering a GUI to change
all the color grading settings. It uses the same test scene as the
existing `tonemapping` example, which has been factored out into a
shared glTF scene.

[CIE 1931]: https://en.wikipedia.org/wiki/CIE_1931_color_space

[D65 standard illuminant]:
https://en.wikipedia.org/wiki/Standard_illuminant#Illuminant_series_D

[LMS color space]: https://en.wikipedia.org/wiki/LMS_color_space

[HSV]: https://en.wikipedia.org/wiki/HSL_and_HSV

[ASC CDL combined function]:
https://en.wikipedia.org/wiki/ASC_CDL#Combined_Function

## Changelog

### Added

* Many new filmic color grading options have been added to the
`ColorGrading` component.

## Migration Guide

* `ColorGrading::gamma` and `ColorGrading::pre_saturation` are now set
separately for the `shadows`, `midtones`, and `highlights` sections. You
can migrate code with the `ColorGrading::all_sections` and
`ColorGrading::all_sections_mut` functions, which access and/or update
all sections at once.
* `ColorGrading::post_saturation` and `ColorGrading::exposure` are now
fields of `ColorGrading::global`.

## Screenshots

![Screenshot 2024-04-27
143144](https://github.com/bevyengine/bevy/assets/157897/c1de5894-917d-4101-b5c9-e644d141a941)

![Screenshot 2024-04-27
143216](https://github.com/bevyengine/bevy/assets/157897/da393c8a-d747-42f5-b47c-6465044c788d)
2024-05-02 12:18:59 +00:00
Patrick Walton
16531fb3e3
Implement GPU frustum culling. (#12889)
This commit implements opt-in GPU frustum culling, built on top of the
infrastructure in https://github.com/bevyengine/bevy/pull/12773. To
enable it on a camera, add the `GpuCulling` component to it. To
additionally disable CPU frustum culling, add the `NoCpuCulling`
component. Note that adding `GpuCulling` without `NoCpuCulling`
*currently* does nothing useful. The reason why `GpuCulling` doesn't
automatically imply `NoCpuCulling` is that I intend to follow this patch
up with GPU two-phase occlusion culling, and CPU frustum culling plus
GPU occlusion culling seems like a very commonly-desired mode.

Adding the `GpuCulling` component to a view puts that view into
*indirect mode*. This mode makes all drawcalls indirect, relying on the
mesh preprocessing shader to allocate instances dynamically. In indirect
mode, the `PreprocessWorkItem` `output_index` points not to a
`MeshUniform` instance slot but instead to a set of `wgpu`
`IndirectParameters`, from which it allocates an instance slot
dynamically if frustum culling succeeds. Batch building has been updated
to allocate and track indirect parameter slots, and the AABBs are now
supplied to the GPU as `MeshCullingData`.

A small amount of code relating to the frustum culling has been borrowed
from meshlets and moved into `maths.wgsl`. Note that standard Bevy
frustum culling uses AABBs, while meshlets use bounding spheres; this
means that not as much code can be shared as one might think.

This patch doesn't provide any way to perform GPU culling on shadow
maps, to avoid making this patch bigger than it already is. That can be
a followup.

## Changelog

### Added

* Frustum culling can now optionally be done on the GPU. To enable it,
add the `GpuCulling` component to a camera.
* To disable CPU frustum culling, add `NoCpuCulling` to a camera. Note
that `GpuCulling` doesn't automatically imply `NoCpuCulling`.
2024-04-28 12:50:00 +00:00
BD103
45bb6253e2
Restore dragons to their seat of power (#13124)
# Objective

- There is an unfortunate lack of dragons in the meshlet docs.
- Dragons are symbolic of majesty, power, storms, and meshlets.
- A dragon habitat such as our docs requires cultivation to ensure each
winged lizard reaches their fullest, fiery selves.

## Solution

- Fix the link to the dragon image.
- The link originally targeted the `meshlet` branch, but that was later
deleted after it was merged into `main`.

---

## Changelog

- Added a dragon back into the `MeshletPlugin` documentation.
2024-04-28 07:20:16 +00:00
JMS55
e1a0da0fa6
Meshlet LOD-compatible two-pass occlusion culling (#12898)
Keeping track of explicit visibility per cluster between frames does not
work with LODs, and leads to worse culling (using the final depth buffer
from the previous frame is more accurate).

Instead, we need to generate a second depth pyramid after the second
raster pass, and then use that in the first culling pass in the next
frame to test if a cluster would have been visible last frame or not.

As part of these changes, the write_index_buffer pass has been folded
into the culling pass for a large performance gain, and to avoid
tracking a lot of extra state that would be needed between passes.

Prepass previous model/view stuff was adapted to work with meshlets as
well.

Also fixed a bug with materials, and other misc improvements.

---------

Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: atlas dostal <rodol@rivalrebels.com>
Co-authored-by: vero <email@atlasdostal.com>
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
Co-authored-by: Robert Swain <robert.swain@gmail.com>
2024-04-28 05:30:20 +00:00
Doonv
de9dc9c204
Fix CameraProjection panic and improve CameraProjectionPlugin (#11808)
# Objective

Fix https://github.com/bevyengine/bevy/issues/11799 and improve
`CameraProjectionPlugin`

## Solution

`CameraProjectionPlugin` is now an all-in-one plugin for adding a custom
`CameraProjection`. I also added `PbrProjectionPlugin` which is like
`CameraProjectionPlugin` but for PBR.

P.S. I'd like to get this merged after
https://github.com/bevyengine/bevy/pull/11766.

---

## Changelog

- Changed `CameraProjectionPlugin` to be an all-in-one plugin for adding
a `CameraProjection`
- Removed `VisibilitySystems::{UpdateOrthographicFrusta,
UpdatePerspectiveFrusta, UpdateProjectionFrusta}`, now replaced with
`VisibilitySystems::UpdateFrusta`
- Added `PbrProjectionPlugin` for projection-specific PBR functionality.

## Migration Guide

`VisibilitySystems`'s `UpdateOrthographicFrusta`,
`UpdatePerspectiveFrusta`, and `UpdateProjectionFrusta` variants were
removed, they were replaced with `VisibilitySystems::UpdateFrusta`
2024-04-26 23:52:09 +00:00
re0312
92928f13ed
Cleanup extract_meshes (#13026)
# Objective

- clean up extract_mesh_(gpu/cpu)_building

## Solution

- gpu_building no need to hold  `prev_render_mesh_instances`
- using `insert_unique_unchecked` instead of simple insert as we know
all entities are unique
- direcly get `previous_input_index ` in par_loop 


## Performance
this should also bring a slight performance win.

cargo run --release --example many_cubes --features bevy/trace_tracy --
--no-frustum-culling
`extract_meshes_for_gpu_building`


![image](https://github.com/bevyengine/bevy/assets/45868716/a5425e8a-258b-482d-afda-170363ee6479)

---------

Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
2024-04-26 23:49:32 +00:00
findmyhappy
36a3e53e10
chore: fix some comments (#13083)
# Objective

remove repetitive words

Signed-off-by: findmyhappy <findhappy@sohu.com>
2024-04-25 19:09:16 +00:00
JMS55
6d6810c90d
Meshlet continuous LOD (#12755)
Adds a basic level of detail system to meshlets. An extremely brief
summary is as follows:
* In `from_mesh.rs`, once we've built the first level of clusters, we
group clusters, simplify the new mega-clusters, and then split the
simplified groups back into regular sized clusters. Repeat several times
(ideally until you can't anymore). This forms a directed acyclic graph
(DAG), where the children are the meshlets from the previous level, and
the parents are the more simplified versions of their children. The leaf
nodes are meshlets formed from the original mesh.
* In `cull_meshlets.wgsl`, each cluster selects whether to render or not
based on the LOD bounding sphere (different than the culling bounding
sphere) of the current meshlet, the LOD bounding sphere of its parent
(the meshlet group from simplification), and the simplification error
relative to its children of both the current meshlet and its parent
meshlet. This kind of breaks two pass occlusion culling, which will be
fixed in a future PR by using an HZB from the previous frame to get the
initial list of occluders.

Many, _many_ improvements to be done in the future
https://github.com/bevyengine/bevy/issues/11518, not least of which is
code quality and speed. I don't even expect this to work on many types
of input meshes. This is just a basic implementation/draft for
collaboration.

Arguable how much we want to do in this PR, I'll leave that up to
maintainers. I've erred on the side of "as basic as possible".

References:
* Slides 27-77 (video available on youtube)
https://advances.realtimerendering.com/s2021/Karis_Nanite_SIGGRAPH_Advances_2021_final.pdf
*
https://blog.traverseresearch.nl/creating-a-directed-acyclic-graph-from-a-mesh-1329e57286e5
*
https://jglrxavpok.github.io/2024/01/19/recreating-nanite-lod-generation.html,
https://jglrxavpok.github.io/2024/03/12/recreating-nanite-faster-lod-generation.html,
https://jglrxavpok.github.io/2024/04/02/recreating-nanite-runtime-lod-selection.html,
and https://github.com/jglrxavpok/Carrot
*
https://github.com/gents83/INOX/tree/master/crates/plugins/binarizer/src
* https://cs418.cs.illinois.edu/website/text/nanite.html


![image](https://github.com/bevyengine/bevy/assets/47158642/e40bff9b-7d0c-4a19-a3cc-2aad24965977)

![image](https://github.com/bevyengine/bevy/assets/47158642/442c7da3-7761-4da7-9acd-37f15dd13e26)

---------

Co-authored-by: Ricky Taylor <rickytaylor26@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: atlas dostal <rodol@rivalrebels.com>
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
2024-04-23 21:43:53 +00:00
JMS55
17633c1f75
Remove unused push constants (#13076)
The shader code was removed in #11280, but we never cleaned up the rust
code.
2024-04-23 21:43:46 +00:00
re0312
0f27500e46
Improve par_iter and Parallel (#12904)
# Objective

- bevy usually use `Parallel::scope` to collect items from `par_iter`,
but `scope` will be called with every satifified items. it will cause a
lot of unnecessary lookup.

## Solution

- similar to Rayon ,we introduce `for_each_init` for `par_iter` which
only be invoked when spawn a task for a group of items.

---

## Changelog

- added  `for_each_init`

## Performance
`check_visibility `  in  `many_foxes ` 

![image](https://github.com/bevyengine/bevy/assets/45868716/030c41cf-0d2f-4a36-a071-35097d93e494)
 
~40% performance gain in `check_visibility`.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2024-04-23 12:05:34 +00:00
François Mockers
c40b485095
use a u64 for MeshPipelineKey (#13015)
# Objective

- `MeshPipelineKey` use some bits for two things
- First commit in this PR adds an assertion that doesn't work currently
on main
- This leads to some mesh topology not working anymore, for example
`LineStrip`
- With examples `lines`, there should be two groups of lines, the blue
one doesn't display currently

## Solution

- Change the `MeshPipelineKey` to be backed by a `u64` instead, to have
enough bits
2024-04-21 20:01:45 +00:00
IceSentry
8403c41c67
Use WireframeColor to override global color (#13034)
# Objective

- The docs says the WireframeColor is supposed to override the default
global color but it doesn't.

## Solution

- Use WireframeColor to override global color like docs said it was
supposed to do.
- Updated the example to document this feature
- I also took the opportunity to clean up the code a bit

Fixes #13032
2024-04-20 13:59:12 +00:00
Brezak
f68bc01544
Run CheckVisibility after all the other visibility system sets have… (#12962)
# Objective

Make visibility system ordering explicit. Fixes #12953.

## Solution

Specify `CheckVisibility` happens after all other `VisibilitySystems`
sets have happened.

---------

Co-authored-by: Elabajaba <Elabajaba@users.noreply.github.com>
2024-04-18 20:33:29 +00:00
charlotte
ef7bafa68e
Add missing Default impl to ExtendedMaterial. (#13008)
# Objective

When trying to be generic over `Material + Default`, the lack of a
`Default` impl for `ExtendedMaterial`, even when both of its components
implement `Default`, is problematic. I think was probably just
overlooked.

## Solution

Impl `Default` if the material and extension both impl `Default`.

---

## Changelog

## Migration Guide
2024-04-18 12:57:14 +00:00
Brezak
368c5cef1a
Implement clone for most bundles. (#12993)
# Objective

Closes #12985.

## Solution

- Derive clone for most types with bundle in their name.
- Bundle types missing clone:
-
[`TextBundle`](https://docs.rs/bevy/latest/bevy/prelude/struct.TextBundle.html)
(Contains
[`ContentSize`](https://docs.rs/bevy/latest/bevy/ui/struct.ContentSize.html)
which can't be cloned because it itself contains a `Option<MeasureFunc>`
where
[`MeasureFunc`](https://docs.rs/taffy/0.3.18/taffy/node/enum.MeasureFunc.html)
isn't clone)
-
[`ImageBundle`](https://docs.rs/bevy/latest/bevy/prelude/struct.ImageBundle.html)
(Same as `TextBundle`)
-
[`AtlasImageBundle`](https://docs.rs/bevy/latest/bevy/prelude/struct.AtlasImageBundle.html)
(Will be deprecated in 0.14 there's no point)
2024-04-16 16:37:09 +00:00
Patrick Walton
6003a317b8
Add Cascades to the type registry, fixing lights in glTF. (#12989)
glTF files that contain lights currently panic when loaded into Bevy,
because Bevy tries to reflect on `Cascades`, which accidentally wasn't
registered.
2024-04-16 05:16:45 +00:00
BD103
7b8d502083
Fix beta lints (#12980)
# Objective

- Fixes #12976

## Solution

This one is a doozy.

- Run `cargo +beta clippy --workspace --all-targets --all-features` and
fix all issues
- This includes:
- Moving inner attributes to be outer attributes, when the item in
question has both inner and outer attributes
  - Use `ptr::from_ref` in more scenarios
- Extend the valid idents list used by `clippy:doc_markdown` with more
names
  - Use `Clone::clone_from` when possible
  - Remove redundant `ron` import
  - Add backticks to **so many** identifiers and items
    - I'm sorry whoever has to review this

---

## Changelog

- Added links to more identifiers in documentation.
2024-04-16 02:46:46 +00:00
Patrick Walton
1141e731ff
Implement alpha to coverage (A2C) support. (#12970)
[Alpha to coverage] (A2C) replaces alpha blending with a
hardware-specific multisample coverage mask when multisample
antialiasing is in use. It's a simple form of [order-independent
transparency] that relies on MSAA. ["Anti-aliased Alpha Test: The
Esoteric Alpha To Coverage"] is a good summary of the motivation for and
best practices relating to A2C.

This commit implements alpha to coverage support as a new variant for
`AlphaMode`. You can supply `AlphaMode::AlphaToCoverage` as the
`alpha_mode` field in `StandardMaterial` to use it. When in use, the
standard material shader automatically applies the texture filtering
method from ["Anti-aliased Alpha Test: The Esoteric Alpha To Coverage"].
Objects with alpha-to-coverage materials are binned in the opaque pass,
as they're fully order-independent.

The `transparency_3d` example has been updated to feature an object with
alpha to coverage. Happily, the example was already using MSAA.

This is part of #2223, as far as I can tell.

[Alpha to coverage]: https://en.wikipedia.org/wiki/Alpha_to_coverage

[order-independent transparency]:
https://en.wikipedia.org/wiki/Order-independent_transparency

["Anti-aliased Alpha Test: The Esoteric Alpha To Coverage"]:
https://bgolus.medium.com/anti-aliased-alpha-test-the-esoteric-alpha-to-coverage-8b177335ae4f

---

## Changelog

### Added

* The `AlphaMode` enum now supports `AlphaToCoverage`, to provide
limited order-independent transparency when multisample antialiasing is
in use.
2024-04-15 20:37:52 +00:00
re0312
09a1f94d14
fix shadow pass trace (#12977)
# Objective

- shadow pass trace does not work correctly

## Solution

- enable it.
2024-04-15 15:55:39 +00:00
Robert Swain
5f05e75a70
Fix 2D BatchedInstanceBuffer clear (#12922)
# Objective

- `cargo run --release --example bevymark -- --benchmark --waves 160
--per-wave 1000 --mode mesh2d` runs slower and slower over time due to
`no_gpu_preprocessing::write_batched_instance_buffer<bevy_sprite::mesh2d::mesh::Mesh2dPipeline>`
taking longer and longer because the `BatchedInstanceBuffer` is not
cleared

## Solution

- Split the `clear_batched_instance_buffers` system into CPU and GPU
versions
- Use the CPU version for 2D meshes
2024-04-15 05:00:43 +00:00
Patrick Walton
8577a448f7
Fix rendering of sprites, text, and meshlets after #12582. (#12945)
`Sprite`, `Text`, and `Handle<MeshletMesh>` were types of renderable
entities that the new segregated visible entity system didn't handle, so
they didn't appear.

Because `bevy_text` depends on `bevy_sprite`, and the visibility
computation of text happens in the latter crate, I had to introduce a
new marker component, `SpriteSource`. `SpriteSource` marks entities that
aren't themselves sprites but become sprites during rendering. I added
this component to `Text2dBundle`. Unfortunately, this is technically a
breaking change, although I suspect it won't break anybody in practice
except perhaps editors.

Fixes #12935.

## Changelog

### Changed

* `Text2dBundle` now includes a new marker component, `SpriteSource`.
Bevy uses this internally to optimize visibility calculation.

## Migration Guide

* `Text` now requires a `SpriteSource` marker component in order to
appear. This component has been added to `Text2dBundle`.
2024-04-13 14:15:00 +00:00
Patrick Walton
5caf085dac
Divide the single VisibleEntities list into separate lists for 2D meshes, 3D meshes, lights, and UI elements, for performance. (#12582)
This commit splits `VisibleEntities::entities` into four separate lists:
one for lights, one for 2D meshes, one for 3D meshes, and one for UI
elements. This allows `queue_material_meshes` and similar methods to
avoid examining entities that are obviously irrelevant. In particular,
this separation helps scenes with many skinned meshes, as the individual
bones are considered visible entities but have no rendered appearance.

Internally, `VisibleEntities::entities` is a `HashMap` from the `TypeId`
representing a `QueryFilter` to the appropriate `Entity` list. I had to
do this because `VisibleEntities` is located within an upstream crate
from the crates that provide lights (`bevy_pbr`) and 2D meshes
(`bevy_sprite`). As an added benefit, this setup allows apps to provide
their own types of renderable components, by simply adding a specialized
`check_visibility` to the schedule.

This provides a 16.23% end-to-end speedup on `many_foxes` with 10,000
foxes (24.06 ms/frame to 20.70 ms/frame).

## Migration guide

* `check_visibility` and `VisibleEntities` now store the four types of
renderable entities--2D meshes, 3D meshes, lights, and UI
elements--separately. If your custom rendering code examines
`VisibleEntities`, it will now need to specify which type of entity it's
interested in using the `WithMesh2d`, `WithMesh`, `WithLight`, and
`WithNode` types respectively. If your app introduces a new type of
renderable entity, you'll need to add an explicit call to
`check_visibility` to the schedule to accommodate your new component or
components.

## Analysis

`many_foxes`, 10,000 foxes: `main`:
![Screenshot 2024-03-31
114444](https://github.com/bevyengine/bevy/assets/157897/16ecb2ff-6e04-46c0-a4b0-b2fde2084bad)

`many_foxes`, 10,000 foxes, this branch:
![Screenshot 2024-03-31
114256](https://github.com/bevyengine/bevy/assets/157897/94dedae4-bd00-45b2-9aaf-dfc237004ddb)

`queue_material_meshes` (yellow = this branch, red = `main`):
![Screenshot 2024-03-31
114637](https://github.com/bevyengine/bevy/assets/157897/f90912bd-45bd-42c4-bd74-57d98a0f036e)

`queue_shadows` (yellow = this branch, red = `main`):
![Screenshot 2024-03-31
114607](https://github.com/bevyengine/bevy/assets/157897/6ce693e3-20c0-4234-8ec9-a6f191299e2d)
2024-04-11 20:33:20 +00:00
Patrick Walton
d59b1e71ef
Implement percentage-closer filtering (PCF) for point lights. (#12910)
I ported the two existing PCF techniques to the cubemap domain as best I
could. Generally, the technique is to create a 2D orthonormal basis
using Gram-Schmidt normalization, then apply the technique over that
basis. The results look fine, though the shadow bias often needs
adjusting.

For comparison, Unity uses a 4-tap pattern for PCF on point lights of
(1, 1, 1), (-1, -1, 1), (-1, 1, -1), (1, -1, -1). I tried this but
didn't like the look, so I went with the design above, which ports the
2D techniques to the 3D domain. There's surprisingly little material on
point light PCF.

I've gone through every example using point lights and verified that the
shadow maps look fine, adjusting biases as necessary.

Fixes #3628.

---

## Changelog

### Added
* Shadows from point lights now support percentage-closer filtering
(PCF), and as a result look less aliased.

### Changed
* `ShadowFilteringMethod::Castano13` and
`ShadowFilteringMethod::Jimenez14` have been renamed to
`ShadowFilteringMethod::Gaussian` and `ShadowFilteringMethod::Temporal`
respectively.

## Migration Guide

* `ShadowFilteringMethod::Castano13` and
`ShadowFilteringMethod::Jimenez14` have been renamed to
`ShadowFilteringMethod::Gaussian` and `ShadowFilteringMethod::Temporal`
respectively.
2024-04-10 20:16:08 +00:00
Vitaliy Sapronenko
ddcbb3cc80
flipping texture coords methods has been added to the StandardMaterial (#12917)
# Objective

Fixes #11996 
The deprecated shape Quad's flip field role migrated to
StandardMaterial's flip/flipped methods

## Solution

flip/flipping methods of StandardMaterial is applicable to any mesh

---

## Changelog

- Added flip and flipped methods to the StandardMaterial implementation
- Added FLIP_HORIZONTAL, FLIP_VERTICAL, FLIP_X, FLIP_Y, FLIP_Z constants

## Migration Guide

Instead of using `Quad::flip` field, call `flipped(true, false)` method
on the StandardMaterial instance when adding the mesh.

---------

Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-04-10 18:23:55 +00:00
Patrick Walton
11817f4ba4
Generate MeshUniforms on the GPU via compute shader where available. (#12773)
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`:
![Screenshot 2024-04-02
124842](https://github.com/bevyengine/bevy/assets/157897/a6748ea4-dd05-47b6-9254-45d07d33cb10)
It's notable that we get a small win even though we're now writing to a
GPU buffer.

`queue_material_meshes`:
![Screenshot 2024-04-02
124911](https://github.com/bevyengine/bevy/assets/157897/ecb44d78-65dc-448d-ba85-2de91aa2ad94)
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`:
![Screenshot 2024-04-02
125123](https://github.com/bevyengine/bevy/assets/157897/4e20fc86-f9dd-4e5c-8623-837e4258f435)
There's a huge win here, enough to make batching basically drop off the
profile.

`write_batched_instance_buffer`:
![Screenshot 2024-04-02
125237](https://github.com/bevyengine/bevy/assets/157897/401a5c32-9dc1-4991-996d-eb1cac6014b2)
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`.
2024-04-10 05:33:32 +00:00