extended material example

src/main.rs

@@ -0,0 +1,76 @@
+//! Demonstrates using a custom extension to the `StandardMaterial` to modify the results of the builtin pbr shader.
+
+use bevy::{
+    color::palettes::basic::RED,
+    pbr::{ExtendedMaterial, MaterialExtension, OpaqueRendererMethod},
+    prelude::*,
+    render::render_resource::*,
+};
+
+/// This example uses a shader source file from the assets subdirectory
+const SHADER_ASSET_PATH: &str = "shaders/material.wgsl";
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_plugins(MaterialPlugin::<
+            ExtendedMaterial<StandardMaterial, MyExtension>,
+        >::default())
+        .add_systems(Startup, setup)
+        .add_systems(Update, rotate_things)
+        .run();
+}
+
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<ExtendedMaterial<StandardMaterial, MyExtension>>>,
+) {
+    // sphere
+    commands.spawn((
+        Mesh3d(meshes.add(Sphere::new(1.0))),
+        MeshMaterial3d(materials.add(ExtendedMaterial {
+            base: StandardMaterial {
+                base_color: RED.into(),
+                opaque_render_method: OpaqueRendererMethod::Auto,
+                ..Default::default()
+            },
+            extension: MyExtension { quantize_steps: 3 },
+        })),
+        Transform::from_xyz(0.0, 0.5, 0.0),
+    ));
+
+    // light
+    commands.spawn((
+        DirectionalLight::default(),
+        Transform::from_xyz(1.0, 1.0, 1.0).looking_at(Vec3::ZERO, Vec3::Y),
+        Rotate,
+    ));
+
+    // camera
+    commands.spawn((
+        Camera3d::default(),
+        Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
+    ));
+}
+
+#[derive(Component)]
+struct Rotate;
+
+fn rotate_things(mut q: Query<&mut Transform, With<Rotate>>, time: Res<Time>) {
+    for mut t in &mut q {
+        t.rotate_y(time.delta_secs());
+    }
+}
+
+#[derive(Asset, AsBindGroup, Reflect, Debug, Clone)]
+struct MyExtension {
+    #[uniform(100)]
+    quantize_steps: u32,
+}
+
+impl MaterialExtension for MyExtension {
+    fn fragment_shader() -> ShaderRef {
+        SHADER_ASSET_PATH.into()
+    }
+}