bevyengine#5409

assets/shaders/custom_material.wgsl

@@ -1,3 +1,5 @@
+#import bevy_pbr::mesh_view_bindings
+
 struct CustomMaterial {
     color: vec4<f32>,
 };
@@ -13,5 +15,8 @@ var base_color_sampler: sampler;
 fn fragment(
     #import bevy_pbr::mesh_vertex_output
 ) -> @location(0) vec4<f32> {
-    return material.color * textureSample(base_color_texture, base_color_sampler, uv);
+    let time = sin(globals.time) * 0.5 + 0.5;
+    return material.color
+        * textureSample(base_color_texture, base_color_sampler, uv)
+        * vec4<f32>(time, time, time, 1.0);
 }

crates/bevy_pbr/src/render/mesh.rs

@@ -13,6 +13,7 @@ use bevy_math::{Mat4, Vec2};
 use bevy_reflect::TypeUuid;
 use bevy_render::{
     extract_component::{ComponentUniforms, DynamicUniformIndex, UniformComponentPlugin},
+    globals::{GlobalsBuffer, GlobalsUniform},
     mesh::{
         skinning::{SkinnedMesh, SkinnedMeshInverseBindposes},
         GpuBufferInfo, Mesh, MeshVertexBufferLayout,
@@ -377,6 +378,16 @@ impl FromWorld for MeshPipeline {
                     },
                     count: None,
                 },
+                BindGroupLayoutEntry {
+                    binding: 9,
+                    visibility: ShaderStages::VERTEX_FRAGMENT,
+                    ty: BindingType::Buffer {
+                        ty: BufferBindingType::Uniform,
+                        has_dynamic_offset: false,
+                        min_binding_size: Some(GlobalsUniform::min_size()),
+                    },
+                    count: None,
+                },
             ],
             label: Some("mesh_view_layout"),
         });
@@ -463,6 +474,7 @@ impl FromWorld for MeshPipeline {
                 ),
             }
         };
+
         MeshPipeline {
             view_layout,
             mesh_layout,
@@ -757,11 +769,13 @@ pub fn queue_mesh_view_bind_groups(
     global_light_meta: Res<GlobalLightMeta>,
     view_uniforms: Res<ViewUniforms>,
     views: Query<(Entity, &ViewShadowBindings, &ViewClusterBindings)>,
+    globals_buffer: Res<GlobalsBuffer>,
 ) {
-    if let (Some(view_binding), Some(light_binding), Some(point_light_binding)) = (
+    if let (Some(view_binding), Some(light_binding), Some(point_light_binding), Some(globals)) = (
         view_uniforms.uniforms.binding(),
         light_meta.view_gpu_lights.binding(),
         global_light_meta.gpu_point_lights.binding(),
+        globals_buffer.buffer.binding(),
     ) {
         for (entity, view_shadow_bindings, view_cluster_bindings) in &views {
             let view_bind_group = render_device.create_bind_group(&BindGroupDescriptor {
@@ -808,6 +822,10 @@ pub fn queue_mesh_view_bind_groups(
                         binding: 8,
                         resource: view_cluster_bindings.offsets_and_counts_binding().unwrap(),
                     },
+                    BindGroupEntry {
+                        binding: 9,
+                        resource: globals.clone(),
+                    },
                 ],
                 label: Some("mesh_view_bind_group"),
                 layout: &mesh_pipeline.view_layout,

crates/bevy_pbr/src/render/mesh_view_bindings.wgsl

@@ -40,3 +40,6 @@ var<storage> cluster_light_index_lists: ClusterLightIndexLists;
 @group(0) @binding(8)
 var<storage> cluster_offsets_and_counts: ClusterOffsetsAndCounts;
 #endif
+
+@group(0) @binding(9)
+var<uniform> globals: Globals;

crates/bevy_pbr/src/render/mesh_view_types.wgsl

@@ -85,3 +85,10 @@ struct ClusterOffsetsAndCounts {
     data: array<vec4<u32>>,
 };
 #endif
+
+struct Globals {
+    // The time since startup in seconds
+    time: f32,
+    // The delta time of the previous frame in seconds
+    delta_time: f32,
+}

crates/bevy_render/src/globals.rs

@@ -0,0 +1,60 @@
+use crate::{
+    extract_resource::ExtractResource,
+    render_resource::{ShaderType, UniformBuffer},
+    renderer::{RenderDevice, RenderQueue},
+    Extract, RenderApp, RenderStage,
+};
+use bevy_app::{App, Plugin};
+use bevy_ecs::prelude::*;
+use bevy_reflect::Reflect;
+use bevy_time::Time;
+
+pub struct GlobalsPlugin;
+
+impl Plugin for GlobalsPlugin {
+    fn build(&self, app: &mut App) {
+        if let Ok(render_app) = app.get_sub_app_mut(RenderApp) {
+            render_app
+                .init_resource::<GlobalsBuffer>()
+                .init_resource::<Time>()
+                .add_system_to_stage(RenderStage::Extract, extract_time)
+                .add_system_to_stage(RenderStage::Prepare, prepare_globals_buffer);
+        }
+    }
+}
+
+fn extract_time(mut commands: Commands, time: Extract<Res<Time>>) {
+    commands.insert_resource(time.clone());
+}
+
+/// Contains global values useful when writing shaders.
+/// Currently only contains values related to time.
+#[derive(Default, Clone, ExtractResource, Reflect, ShaderType)]
+#[reflect(Resource)]
+pub struct GlobalsUniform {
+    /// The time since startup in seconds
+    time: f32,
+    /// The duration of the last frame in seconds
+    delta_time: f32,
+}
+
+/// The buffer containing the [`GlobalsUniform`]
+#[derive(Component, Default)]
+pub struct GlobalsBuffer {
+    pub buffer: UniformBuffer<GlobalsUniform>,
+}
+
+fn prepare_globals_buffer(
+    render_device: Res<RenderDevice>,
+    render_queue: Res<RenderQueue>,
+    mut globals_buffer: ResMut<GlobalsBuffer>,
+    time: Res<Time>,
+) {
+    let buffer = globals_buffer.buffer.get_mut();
+    buffer.time = time.seconds_since_startup() as f32;
+    buffer.delta_time = time.delta_seconds();
+
+    globals_buffer
+        .buffer
+        .write_buffer(&render_device, &render_queue);
+}

crates/bevy_render/src/lib.rs

@@ -5,6 +5,7 @@ pub mod color;
 pub mod extract_component;
 mod extract_param;
 pub mod extract_resource;
+pub mod globals;
 pub mod mesh;
 pub mod primitives;
 pub mod rangefinder;
@@ -33,6 +34,7 @@ pub mod prelude {
     };
 }
 
+use globals::GlobalsPlugin;
 pub use once_cell;
 
 use crate::{
@@ -321,7 +323,8 @@ impl Plugin for RenderPlugin {
             .add_plugin(MeshPlugin)
             // NOTE: Load this after renderer initialization so that it knows about the supported
             // compressed texture formats
-            .add_plugin(ImagePlugin);
+            .add_plugin(ImagePlugin)
+            .add_plugin(GlobalsPlugin);
     }
 }