This commit implements a large subset of [*subpixel morphological
antialiasing*], better known as SMAA. SMAA is a 2011 antialiasing
technique that detects jaggies in an aliased image and smooths them out.
Despite its age, it's been a continual staple of games for over a
decade. Four quality presets are available: *low*, *medium*, *high*, and
*ultra*. I set the default to *high*, on account of modern GPUs being
significantly faster than they were in 2011.
Like the already-implemented FXAA, SMAA works on an unaliased image.
Unlike FXAA, it requires three passes: (1) edge detection; (2) blending
weight calculation; (3) neighborhood blending. Each of the first two
passes writes an intermediate texture for use by the next pass. The
first pass also writes to a stencil buffer in order to dramatically
reduce the number of pixels that the second pass has to examine. Also
unlike FXAA, two built-in lookup textures are required; I bundle them
into the library in compressed KTX2 format.
The [reference implementation of SMAA] is in HLSL, with abundant use of
preprocessor macros to achieve GLSL compatibility. Unfortunately, the
reference implementation predates WGSL by over a decade, so I had to
translate the HLSL to WGSL manually. As much as was reasonably possible
without sacrificing readability, I tried to translate line by line,
preserving comments, both to aid reviewing and to allow patches to the
HLSL to more easily apply to the WGSL. Most of SMAA's features are
supported, but in the interests of making this patch somewhat less huge,
I skipped a few of the more exotic ones:
* The temporal variant is currently unsupported. This is and has been
used in shipping games, so supporting temporal SMAA would be useful
follow-up work. It would, however, require some significant work on TAA
to ensure compatibility, so I opted to skip it in this patch.
* Depth- and chroma-based edge detection are unimplemented; only luma
is. Depth is lower-quality, but faster; chroma is higher-quality, but
slower. Luma is the suggested default edge detection algorithm. (Note
that depth-based edge detection wouldn't work on WebGL 2 anyway, because
of the Naga bug whereby depth sampling is miscompiled in GLSL. This is
the same bug that prevents depth of field from working on that
platform.)
* Predicated thresholding is currently unsupported.
* My implementation is incompatible with SSAA and MSAA, unlike the
original; MSAA must be turned off to use SMAA in Bevy. I believe this
feature was rarely used in practice.
The `anti_aliasing` example has been updated to allow experimentation
with and testing of the different SMAA quality presets. Along the way, I
refactored the example's help text rendering code a bit to eliminate
code repetition.
SMAA is fully supported on WebGL 2.
Fixes#9819.
[*subpixel morphological antialiasing*]: https://www.iryoku.com/smaa/
[reference implementation of SMAA]: https://github.com/iryoku/smaa
## Changelog
### Added
* Subpixel morphological antialiasing, or SMAA, is now available. To use
it, add the `SmaaSettings` component to your `Camera`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
This commit implements support for physically-based anisotropy in Bevy's
`StandardMaterial`, following the specification for the
[`KHR_materials_anisotropy`] glTF extension.
[*Anisotropy*] (not to be confused with [anisotropic filtering]) is a
PBR feature that allows roughness to vary along the tangent and
bitangent directions of a mesh. In effect, this causes the specular
light to stretch out into lines instead of a round lobe. This is useful
for modeling brushed metal, hair, and similar surfaces. Support for
anisotropy is a common feature in major game and graphics engines;
Unity, Unreal, Godot, three.js, and Blender all support it to varying
degrees.
Two new parameters have been added to `StandardMaterial`:
`anisotropy_strength` and `anisotropy_rotation`. Anisotropy strength,
which ranges from 0 to 1, represents how much the roughness differs
between the tangent and the bitangent of the mesh. In effect, it
controls how stretched the specular highlight is. Anisotropy rotation
allows the roughness direction to differ from the tangent of the model.
In addition to these two fixed parameters, an *anisotropy texture* can
be supplied. Such a texture should be a 3-channel RGB texture, where the
red and green values specify a direction vector using the same
conventions as a normal map ([0, 1] color values map to [-1, 1] vector
values), and the the blue value represents the strength. This matches
the format that the [`KHR_materials_anisotropy`] specification requires.
Such textures should be loaded as linear and not sRGB. Note that this
texture does consume one additional texture binding in the standard
material shader.
The glTF loader has been updated to properly parse the
`KHR_materials_anisotropy` extension.
A new example, `anisotropy`, has been added. This example loads and
displays the barn lamp example from the [`glTF-Sample-Assets`]
repository. Note that the textures were rather large, so I shrunk them
down and converted them to a mixture of JPEG and KTX2 format, in the
interests of saving space in the Bevy repository.
[*Anisotropy*]:
https://google.github.io/filament/Filament.md.html#materialsystem/anisotropicmodel
[anisotropic filtering]:
https://en.wikipedia.org/wiki/Anisotropic_filtering
[`KHR_materials_anisotropy`]:
https://github.com/KhronosGroup/glTF/blob/main/extensions/2.0/Khronos/KHR_materials_anisotropy/README.md
[`glTF-Sample-Assets`]:
https://github.com/KhronosGroup/glTF-Sample-Assets/
## Changelog
### Added
* Physically-based anisotropy is now available for materials, which
enhances the look of surfaces such as brushed metal or hair. glTF scenes
can use the new feature with the `KHR_materials_anisotropy` extension.
## Screenshots
With anisotropy:
Without anisotropy:
# Objective
- Ever since #13177, the `check-example-showcase-patches-still-work` job
has been failing in the merge queue.
- Specifically, the `asset-source-website.patch` file which modifies
`bevy_asset`'s `lib.rs`.
## Solution
- Re-create the patch.
- Due to new content being added, the line numbers were off.
- Also, turns out that `typos` was checking patch files. This turned
into a CI error, so I disabled that too. Patches shouldn't really be
modified manually, the original source should be. (Also it was erroring
on the commit hash.)
## Testing
- Test the new patch works by running `git apply
tools/example-showcase/asset-source-website.patch`.
- Verify the merge queue passes with the
`check-example-showcase-patches-still-work` job succeeding.
# Objective
- Avoid misspellings throughout the codebase by using
[`typos`](https://github.com/crate-ci/typos) in CI
Inspired by https://github.com/gfx-rs/wgpu/pull/5191
Typos is a minimal code speller written in rust that finds and corrects
spelling mistakes among source code.
- Fast enough to run on monorepos
- Low false positives so you can run on PRs
## Solution
- Use
[typos-action](https://github.com/marketplace/actions/typos-action) in
CI
- Add how to use typos in the Contribution Guide
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
