extended_material/
extended_material.rs

1//! Demonstrates using a custom extension to the `StandardMaterial` to modify the results of the builtin pbr shader.
2
3use bevy::{
4    color::palettes::basic::RED,
5    material::OpaqueRendererMethod,
6    pbr::{ExtendedMaterial, MaterialExtension},
7    prelude::*,
8    render::render_resource::*,
9    shader::ShaderRef,
10};
11
12/// This example uses a shader source file from the assets subdirectory
13const SHADER_ASSET_PATH: &str = "shaders/extended_material.wesl";
14
15fn main() {
16    App::new()
17        .add_plugins(DefaultPlugins)
18        .add_plugins(MaterialPlugin::<
19            ExtendedMaterial<StandardMaterial, MyExtension>,
20        >::default())
21        .add_systems(Startup, setup)
22        .add_systems(Update, rotate_things)
23        .run();
24}
25
26fn setup(
27    mut commands: Commands,
28    mut meshes: ResMut<Assets<Mesh>>,
29    mut materials: ResMut<Assets<ExtendedMaterial<StandardMaterial, MyExtension>>>,
30) {
31    // sphere
32    commands.spawn((
33        Mesh3d(meshes.add(Sphere::new(1.0))),
34        MeshMaterial3d(materials.add(ExtendedMaterial {
35            base: StandardMaterial {
36                base_color: RED.into(),
37                // can be used in forward or deferred mode
38                opaque_render_method: OpaqueRendererMethod::Auto,
39                // in deferred mode, only the PbrInput can be modified (uvs, color and other material properties),
40                // in forward mode, the output can also be modified after lighting is applied.
41                // see the fragment shader `extended_material.wesl` for more info.
42                // Note: to run in deferred mode, you must also add a `DeferredPrepass` component to the camera and either
43                // change the above to `OpaqueRendererMethod::Deferred` or add the `DefaultOpaqueRendererMethod` resource.
44                ..Default::default()
45            },
46            extension: MyExtension::new(1),
47        })),
48        Transform::from_xyz(0.0, 0.5, 0.0),
49    ));
50
51    // light
52    commands.spawn((
53        DirectionalLight::default(),
54        Transform::from_xyz(1.0, 1.0, 1.0).looking_at(Vec3::ZERO, Vec3::Y),
55        Rotate,
56    ));
57
58    // camera
59    commands.spawn((
60        Camera3d::default(),
61        Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
62    ));
63}
64
65#[derive(Component)]
66struct Rotate;
67
68fn rotate_things(mut q: Query<&mut Transform, With<Rotate>>, time: Res<Time>) {
69    for mut t in &mut q {
70        t.rotate_y(time.delta_secs());
71    }
72}
73
74#[derive(Asset, AsBindGroup, Reflect, Debug, Clone, Default)]
75struct MyExtension {
76    // We need to ensure that the bindings of the base material and the extension do not conflict,
77    // so we start from binding slot 100, leaving slots 0-99 for the base material.
78    #[uniform(100)]
79    quantize_steps: u32,
80    // Web examples WebGL2 support: structs must be 16 byte aligned.
81    #[cfg(feature = "webgl2")]
82    #[uniform(100)]
83    _webgl2_padding_8b: u32,
84    #[cfg(feature = "webgl2")]
85    #[uniform(100)]
86    _webgl2_padding_12b: u32,
87    #[cfg(feature = "webgl2")]
88    #[uniform(100)]
89    _webgl2_padding_16b: u32,
90}
91impl MyExtension {
92    fn new(quantize_steps: u32) -> Self {
93        Self {
94            quantize_steps,
95            ..default()
96        }
97    }
98}
99
100impl MaterialExtension for MyExtension {
101    fn fragment_shader() -> ShaderRef {
102        SHADER_ASSET_PATH.into()
103    }
104
105    fn deferred_fragment_shader() -> ShaderRef {
106        SHADER_ASSET_PATH.into()
107    }
108}
extended_material/extended_material.rs

extended_material/
extended_material.rs
