54701a844e
This reverts commit 0b5302d96a.
# Objective
- Fixes #18158
- #17482 introduced rendering changes and was merged a bit too fast
## Solution
- Revert #17482 so that it can be redone and rendering changes discussed
before being merged. This will make it easier to compare changes with
main in the known "valid" state
This is not an issue with the work done in #17482 that is still
interesting
97 lines
3.2 KiB
Rust
97 lines
3.2 KiB
Rust
//! Renders a glTF mesh in 2D with a custom vertex attribute.
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use bevy::{
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gltf::GltfPlugin,
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prelude::*,
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reflect::TypePath,
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render::{
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mesh::{MeshVertexAttribute, MeshVertexBufferLayoutRef},
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render_resource::*,
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},
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sprite::{Material2d, Material2dKey, Material2dPlugin},
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};
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/// This example uses a shader source file from the assets subdirectory
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const SHADER_ASSET_PATH: &str = "shaders/custom_gltf_2d.wgsl";
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/// This vertex attribute supplies barycentric coordinates for each triangle.
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///
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/// Each component of the vector corresponds to one corner of a triangle. It's
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/// equal to 1.0 in that corner and 0.0 in the other two. Hence, its value in
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/// the fragment shader indicates proximity to a corner or the opposite edge.
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const ATTRIBUTE_BARYCENTRIC: MeshVertexAttribute =
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MeshVertexAttribute::new("Barycentric", 2137464976, VertexFormat::Float32x3);
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fn main() {
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App::new()
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.insert_resource(AmbientLight {
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color: Color::WHITE,
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brightness: 1.0 / 5.0f32,
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..default()
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})
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.add_plugins((
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DefaultPlugins.set(
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GltfPlugin::default()
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// Map a custom glTF attribute name to a `MeshVertexAttribute`.
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// The glTF file used here has an attribute name with *two*
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// underscores: __BARYCENTRIC
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// One is stripped to do the comparison here.
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.add_custom_vertex_attribute("_BARYCENTRIC", ATTRIBUTE_BARYCENTRIC),
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),
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Material2dPlugin::<CustomMaterial>::default(),
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))
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.add_systems(Startup, setup)
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.run();
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}
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fn setup(
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mut commands: Commands,
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asset_server: Res<AssetServer>,
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mut materials: ResMut<Assets<CustomMaterial>>,
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) {
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// Add a mesh loaded from a glTF file. This mesh has data for `ATTRIBUTE_BARYCENTRIC`.
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let mesh = asset_server.load(
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GltfAssetLabel::Primitive {
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mesh: 0,
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primitive: 0,
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}
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.from_asset("models/barycentric/barycentric.gltf"),
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);
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commands.spawn((
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Mesh2d(mesh),
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MeshMaterial2d(materials.add(CustomMaterial {})),
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Transform::from_scale(150.0 * Vec3::ONE),
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));
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commands.spawn(Camera2d);
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}
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/// This custom material uses barycentric coordinates from
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/// `ATTRIBUTE_BARYCENTRIC` to shade a white border around each triangle. The
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/// thickness of the border is animated using the global time shader uniform.
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#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
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struct CustomMaterial {}
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impl Material2d for CustomMaterial {
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fn vertex_shader() -> ShaderRef {
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SHADER_ASSET_PATH.into()
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}
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fn fragment_shader() -> ShaderRef {
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SHADER_ASSET_PATH.into()
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}
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fn specialize(
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descriptor: &mut RenderPipelineDescriptor,
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layout: &MeshVertexBufferLayoutRef,
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_key: Material2dKey<Self>,
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) -> Result<(), SpecializedMeshPipelineError> {
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let vertex_layout = layout.0.get_layout(&[
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Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
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Mesh::ATTRIBUTE_COLOR.at_shader_location(1),
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ATTRIBUTE_BARYCENTRIC.at_shader_location(2),
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])?;
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descriptor.vertex.buffers = vec![vertex_layout];
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Ok(())
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}
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}
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