# 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`.
# Objective
- bump naga_oil to 0.10
- update shader imports to use rusty syntax
## Migration Guide
naga_oil 0.10 reworks the import mechanism to support more syntax to
make it more rusty, and test for item use before importing to determine
which imports are modules and which are items, which allows:
- use rust-style imports
```
#import bevy_pbr::{
pbr_functions::{alpha_discard as discard, apply_pbr_lighting},
mesh_bindings,
}
```
- import partial paths:
```
#import part::of::path
...
path::remainder::function();
```
which will call to `part::of::path::remainder::function`
- use fully qualified paths without importing:
```
// #import bevy_pbr::pbr_functions
bevy_pbr::pbr_functions::pbr()
```
- use imported items without qualifying
```
#import bevy_pbr::pbr_functions::pbr
// for backwards compatibility the old style is still supported:
// #import bevy_pbr::pbr_functions pbr
...
pbr()
```
- allows most imported items to end with `_` and numbers (naga_oil#30).
still doesn't allow struct members to end with `_` or numbers but it's
progress.
- the vast majority of existing shader code will work without changes,
but will emit "deprecated" warnings for old-style imports. these can be
suppressed with the `allow-deprecated` feature.
- partly breaks overrides (as far as i'm aware nobody uses these yet) -
now overrides will only be applied if the overriding module is added as
an additional import in the arguments to `Composer::make_naga_module` or
`Composer::add_composable_module`. this is necessary to support
determining whether imports are modules or items.
# Objective
cleanup some pbr shader code. improve shader stage io consistency and
make pbr.wgsl (probably many people's first foray into bevy shader code)
a little more human-readable. also fix a couple of small issues with
deferred rendering.
## Solution
mesh_vertex_output:
- rename to forward_io (to align with prepass_io)
- rename `MeshVertexOutput` to `VertexOutput` (to align with prepass_io)
- move `Vertex` from mesh.wgsl into here (to align with prepass_io)
prepass_io:
- remove `FragmentInput`, use `VertexOutput` directly (to align with
forward_io)
- rename `VertexOutput::clip_position` to `position` (to align with
forward_io)
pbr.wgsl:
- restructure so we don't need `#ifdefs` on the actual entrypoint, use
VertexOutput and FragmentOutput in all cases and use #ifdefs to import
the right struct definitions.
- rearrange to make the flow clearer
- move alpha_discard up from `pbr_functions::pbr` to avoid needing to
call it on some branches and not others
- add a bunch of comments
deferred_lighting:
- move ssao into the `!unlit` block to reflect forward behaviour
correctly
- fix compile error with deferred + premultiply_alpha
## Migration Guide
in custom material shaders:
- `pbr_functions::pbr` no longer calls to
`pbr_functions::alpha_discard`. if you were using the `pbr` function in
a custom shader with alpha mask mode you now also need to call
alpha_discard manually
- rename imports of `bevy_pbr::mesh_vertex_output` to
`bevy_pbr::forward_io`
- rename instances of `MeshVertexOutput` to `VertexOutput`
in custom material prepass shaders:
- rename instances of `VertexOutput::clip_position` to
`VertexOutput::position`
# Objective
operate on naga IR directly to improve handling of shader modules.
- give codespan reporting into imported modules
- allow glsl to be used from wgsl and vice-versa
the ultimate objective is to make it possible to
- provide user hooks for core shader functions (to modify light
behaviour within the standard pbr pipeline, for example)
- make automatic binding slot allocation possible
but ... since this is already big, adds some value and (i think) is at
feature parity with the existing code, i wanted to push this now.
## Solution
i made a crate called naga_oil (https://github.com/robtfm/naga_oil -
unpublished for now, could be part of bevy) which manages modules by
- building each module independantly to naga IR
- creating "header" files for each supported language, which are used to
build dependent modules/shaders
- make final shaders by combining the shader IR with the IR for imported
modules
then integrated this into bevy, replacing some of the existing shader
processing stuff. also reworked examples to reflect this.
## Migration Guide
shaders that don't use `#import` directives should work without changes.
the most notable user-facing difference is that imported
functions/variables/etc need to be qualified at point of use, and
there's no "leakage" of visible stuff into your shader scope from the
imports of your imports, so if you used things imported by your imports,
you now need to import them directly and qualify them.
the current strategy of including/'spreading' `mesh_vertex_output`
directly into a struct doesn't work any more, so these need to be
modified as per the examples (e.g. color_material.wgsl, or many others).
mesh data is assumed to be in bindgroup 2 by default, if mesh data is
bound into bindgroup 1 instead then the shader def `MESH_BINDGROUP_1`
needs to be added to the pipeline shader_defs.
# 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>
