83a358bf33
# Objective - The current shader code is misleading since it makes it look like a struct is passed to the bind group 0 but in reality only the color is passed. They just happen to have the exact same memory layout so wgsl doesn't complain and it works. - The struct is defined after the `impl Material` block which is backwards from pretty much every other usage of the `impl` block in bevy. ## Solution - Remove the unnecessary struct in the shader - move the impl block
64 lines
1.8 KiB
Rust
64 lines
1.8 KiB
Rust
//! A shader and a material that uses it.
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use bevy::{
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prelude::*,
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reflect::TypePath,
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render::render_resource::{AsBindGroup, ShaderRef},
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};
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fn main() {
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App::new()
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.add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default()))
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.add_systems(Startup, setup)
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.run();
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}
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/// set up a simple 3D scene
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fn setup(
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mut commands: Commands,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<CustomMaterial>>,
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asset_server: Res<AssetServer>,
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) {
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// cube
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commands.spawn(MaterialMeshBundle {
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mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
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transform: Transform::from_xyz(0.0, 0.5, 0.0),
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material: materials.add(CustomMaterial {
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color: Color::BLUE,
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color_texture: Some(asset_server.load("branding/icon.png")),
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alpha_mode: AlphaMode::Blend,
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}),
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..default()
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});
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// camera
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commands.spawn(Camera3dBundle {
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transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
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..default()
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});
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}
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// This struct defines the data that will be passed to your shader
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#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
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pub struct CustomMaterial {
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#[uniform(0)]
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color: Color,
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#[texture(1)]
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#[sampler(2)]
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color_texture: Option<Handle<Image>>,
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alpha_mode: AlphaMode,
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}
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/// The Material trait is very configurable, but comes with sensible defaults for all methods.
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/// You only need to implement functions for features that need non-default behavior. See the Material api docs for details!
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impl Material for CustomMaterial {
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fn fragment_shader() -> ShaderRef {
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"shaders/custom_material.wgsl".into()
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}
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fn alpha_mode(&self) -> AlphaMode {
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self.alpha_mode
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}
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}
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