//! This example demonstrates how to use a storage buffer with `AsBindGroup` in a custom material. use bevy::{ prelude::*, reflect::TypePath, render::{ render_resource::{AsBindGroup, ShaderRef}, storage::ShaderStorageBuffer, }, }; const SHADER_ASSET_PATH: &str = "shaders/storage_buffer.wgsl"; fn main() { App::new() .add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default())) .add_systems(Startup, setup) .add_systems(Update, update) .run(); } /// set up a simple 3D scene fn setup( mut commands: Commands, mut meshes: ResMut<Assets<Mesh>>, mut buffers: ResMut<Assets<ShaderStorageBuffer>>, mut materials: ResMut<Assets<CustomMaterial>>, ) { // Example data for the storage buffer let color_data: Vec<[f32; 4]> = vec![ [1.0, 0.0, 0.0, 1.0], [0.0, 1.0, 0.0, 1.0], [0.0, 0.0, 1.0, 1.0], [1.0, 1.0, 0.0, 1.0], [0.0, 1.0, 1.0, 1.0], ]; let colors = buffers.add(ShaderStorageBuffer::from(color_data)); // Create the custom material with the storage buffer let custom_material = CustomMaterial { colors }; let material_handle = materials.add(custom_material); commands.insert_resource(CustomMaterialHandle(material_handle.clone())); // Spawn cubes with the custom material for i in -6..=6 { for j in -3..=3 { commands.spawn(( Mesh3d(meshes.add(Cuboid::from_size(Vec3::splat(0.3)))), MeshMaterial3d(material_handle.clone()), Transform::from_xyz(i as f32, j as f32, 0.0), )); } } // Camera commands.spawn(( Camera3d::default(), Transform::from_xyz(0.0, 0.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y), )); } // Update the material color by time fn update( time: Res<Time>, material_handle: Res<CustomMaterialHandle>, mut materials: ResMut<Assets<CustomMaterial>>, mut buffers: ResMut<Assets<ShaderStorageBuffer>>, ) { let material = materials.get_mut(&material_handle.0).unwrap(); let buffer = buffers.get_mut(&material.colors).unwrap(); buffer.set_data( (0..5) .map(|i| { let t = time.elapsed_secs() * 5.0; [ ops::sin(t + i as f32) / 2.0 + 0.5, ops::sin(t + i as f32 + 2.0) / 2.0 + 0.5, ops::sin(t + i as f32 + 4.0) / 2.0 + 0.5, 1.0, ] }) .collect::<Vec<[f32; 4]>>() .as_slice(), ); } // Holds a handle to the custom material #[derive(Resource)] struct CustomMaterialHandle(Handle<CustomMaterial>); // This struct defines the data that will be passed to your shader #[derive(Asset, TypePath, AsBindGroup, Debug, Clone)] struct CustomMaterial { #[storage(0, read_only)] colors: Handle<ShaderStorageBuffer>, } impl Material for CustomMaterial { fn vertex_shader() -> ShaderRef { SHADER_ASSET_PATH.into() } fn fragment_shader() -> ShaderRef { SHADER_ASSET_PATH.into() } }