Fix atmosphere not supporting multiple cameras

Author: stevesloan

_release-content/migration-guides/atmosphere_multicam.md

@@ -0,0 +1,10 @@
+---
+title: "Atmosphere now supports multiple cameras"
+pull_requests: [23113]
+---
+
+Atmosphere now works correctly with multiple cameras. No action is required for most users.
+
+`init_atmosphere_buffer` has been removed, and `AtmosphereBuffer` has been changed from a `Resource` to a `Component` attached to each camera entity.
+
+If you were directly accessing `AtmosphereBuffer` as a resource in a render world system, you'll need to query for it as a component on camera entities instead.

crates/bevy_pbr/src/atmosphere/mod.rs

@@ -85,7 +85,7 @@ use resources::{
 };
 use tracing::warn;
 
-use crate::resources::{init_atmosphere_buffer, write_atmosphere_buffer};
+use crate::resources::prepare_atmosphere_buffers;
 
 use self::resources::{
     prepare_atmosphere_bind_groups, prepare_atmosphere_textures, AtmosphereBindGroupLayouts,
@@ -165,12 +165,7 @@ impl Plugin for AtmospherePlugin {
             .init_gpu_resource::<SpecializedRenderPipelines<RenderSkyBindGroupLayouts>>()
             .add_systems(
                 RenderStartup,
-                (
-                    init_atmosphere_probe_layout,
-                    init_atmosphere_probe_pipeline,
-                    init_atmosphere_buffer,
-                )
-                    .chain(),
+                (init_atmosphere_probe_layout, init_atmosphere_probe_pipeline).chain(),
             )
             .add_systems(
                 Render,
@@ -187,7 +182,7 @@ impl Plugin for AtmospherePlugin {
                     prepare_atmosphere_probe_bind_groups.in_set(RenderSystems::PrepareBindGroups),
                     prepare_atmosphere_transforms.in_set(RenderSystems::PrepareResources),
                     prepare_atmosphere_bind_groups.in_set(RenderSystems::PrepareBindGroups),
-                    write_atmosphere_buffer.in_set(RenderSystems::PrepareResources),
+                    prepare_atmosphere_buffers.in_set(RenderSystems::PrepareResources),
                 ),
             )
             .add_systems(

crates/bevy_pbr/src/atmosphere/resources.rs

@@ -792,32 +792,44 @@ pub(super) fn prepare_atmosphere_bind_groups(
     Ok(())
 }
 
-pub fn init_atmosphere_buffer(mut commands: Commands) {
-    commands.insert_resource(AtmosphereBuffer {
-        buffer: StorageBuffer::from(GpuAtmosphere {
-            ground_albedo: Vec3::ZERO,
-            inner_radius: 0.0,
-            outer_radius: 0.0,
-            world_to_atmosphere: Mat4::IDENTITY,
-        }),
-    });
+#[derive(ShaderType)]
+#[repr(C)]
+pub(crate) struct AtmosphereData {
+    pub atmosphere: GpuAtmosphere,
+    pub settings: GpuAtmosphereSettings,
 }
 
-#[derive(Resource)]
+#[derive(Component)]
 pub struct AtmosphereBuffer {
-    pub(crate) buffer: StorageBuffer<GpuAtmosphere>,
+    pub(crate) buffer: StorageBuffer<AtmosphereData>,
 }
 
-pub(crate) fn write_atmosphere_buffer(
+pub(crate) fn prepare_atmosphere_buffers(
     device: Res<RenderDevice>,
     queue: Res<RenderQueue>,
-    atmosphere_entity: Query<&GpuAtmosphere, With<Camera3d>>,
-    mut atmosphere_buffer: ResMut<AtmosphereBuffer>,
+    mut views: Query<
+        (
+            Entity,
+            &GpuAtmosphere,
+            &GpuAtmosphereSettings,
+            Option<&mut AtmosphereBuffer>,
+        ),
+        With<ExtractedAtmosphere>,
+    >,
+    mut commands: Commands,
 ) {
-    let Ok(atmosphere) = atmosphere_entity.single() else {
-        return;
-    };
-
-    atmosphere_buffer.buffer.set(atmosphere.clone());
-    atmosphere_buffer.buffer.write_buffer(&device, &queue);
+    for (entity, atmosphere, settings, existing_buffer) in &mut views {
+        let data = AtmosphereData {
+            atmosphere: atmosphere.clone(),
+            settings: settings.clone(),
+        };
+        if let Some(mut atmosphere_buffer) = existing_buffer {
+            atmosphere_buffer.buffer.set(data);
+            atmosphere_buffer.buffer.write_buffer(&device, &queue);
+        } else {
+            let mut buffer = StorageBuffer::from(data);
+            buffer.write_buffer(&device, &queue);
+            commands.entity(entity).insert(AtmosphereBuffer { buffer });
+        }
+    }
 }

crates/bevy_pbr/src/render/mesh.rs

@@ -1,6 +1,7 @@
 use crate::contact_shadows::ViewContactShadowsUniformOffset;
 use crate::{
-    material_bind_groups::MaterialBindGroupSlot, resources::write_atmosphere_buffer,
+    material_bind_groups::{MaterialBindGroupIndex, MaterialBindGroupSlot},
+    resources::prepare_atmosphere_buffers,
     skin::skin_uniforms_from_world,
 };
 use alloc::sync::Arc;
@@ -214,7 +215,7 @@ impl Plugin for MeshRenderPlugin {
                         prepare_mesh_view_bind_groups
                             .in_set(RenderSystems::PrepareBindGroups)
                             .after(prepare_oit_buffers)
-                            .after(write_atmosphere_buffer),
+                            .after(prepare_atmosphere_buffers),
                         no_gpu_preprocessing::clear_batched_cpu_instance_buffers::<MeshPipeline>
                             .in_set(RenderSystems::Cleanup)
                             .after(RenderSystems::Render),

crates/bevy_pbr/src/render/mesh_view_bindings.rs

@@ -630,6 +630,7 @@ pub fn prepare_mesh_view_bind_groups(
         Option<&RenderViewLightProbes<IrradianceVolume>>,
         Has<OrderIndependentTransparencySettings>,
         Option<&AtmosphereTextures>,
+        Option<&AtmosphereBuffer>,
         Has<ExtractedAtmosphere>,
         Option<&ViewContactShadowsUniformOffset>,
     )>,
@@ -648,10 +649,9 @@ pub fn prepare_mesh_view_bind_groups(
         Res<ContactShadowsBuffer>,
     ),
     oit_buffers: Res<OitBuffers>,
-    (decals_buffer, render_decals, atmosphere_buffer, atmosphere_sampler, blue_noise, ltc_luts): (
+    (decals_buffer, render_decals, atmosphere_sampler, blue_noise, ltc_luts): (
         Res<DecalsBuffer>,
         Res<RenderClusteredDecals>,
-        Option<Res<AtmosphereBuffer>>,
         Option<Res<AtmosphereSampler>>,
         Res<Bluenoise>,
         Res<LtcLuts>,
@@ -695,6 +695,7 @@ pub fn prepare_mesh_view_bind_groups(
             render_view_irradiance_volumes,
             has_oit,
             atmosphere_textures,
+            atmosphere_buffer,
             has_atmosphere,
             _contact_shadows_offset,
         ) in &views
@@ -807,7 +808,7 @@ pub fn prepare_mesh_view_bind_groups(
 
             if has_atmosphere
                 && let Some(atmosphere_textures) = atmosphere_textures
-                && let Some(atmosphere_buffer) = atmosphere_buffer.as_ref()
+                && let Some(atmosphere_buffer) = atmosphere_buffer
                 && let Some(atmosphere_sampler) = atmosphere_sampler.as_ref()
                 && let Some(atmosphere_buffer_binding) = atmosphere_buffer.buffer.binding()
             {