Fix errors when disabling gpu clustering

crates/bevy_light/src/cluster/assign.rs

@@ -176,7 +176,7 @@ pub(crate) fn assign_objects_to_clusters(
 
     clusterable_objects.clear();
 
-    // Collect clusterable objects if GPU clustering is enabled.
+    // Collect clusterable objects if GPU clustering is disabled.
     if global_cluster_settings.gpu_clustering.is_none() {
         // collect just the relevant query data into a persisted vec to avoid reallocating each frame
         clusterable_objects.extend(point_lights_query.iter().filter_map(

crates/bevy_pbr/src/cluster/mod.rs

@@ -13,7 +13,7 @@ use bevy_math::{uvec4, UVec3, UVec4, Vec4};
 use bevy_render::{
     render_resource::{
         BindingResource, BufferBindingType, BufferUsages, DownlevelFlags, RawBufferVec, ShaderSize,
-        ShaderType, StorageBuffer, UniformBuffer, UninitBufferVec,
+        ShaderType, StorageBuffer, UniformBuffer,
     },
     renderer::{RenderAdapter, RenderDevice, RenderQueue},
     sync_world::{MainEntity, RenderEntity},
@@ -71,9 +71,12 @@ pub(crate) fn make_global_cluster_settings(world: &World) -> GlobalClusterSettin
     // We need to support compute shaders to use GPU clustering. To deal with
     // the `WGPU_SETTINGS_PRIO="webgl2"` environment setting, we check the
     // `RenderDevice` limits in addition to the `RenderAdapter`.
+    //
     // Some android devices report the capabilities and limits wrong, so we can't rely on them.
     // See <https://github.com/bevyengine/bevy/issues/23208> for Android issues
-    let gpu_clustering_supported = !cfg!(target_os = "android")
+    //
+    // GPU clustering doesn't work properly on iOS simulator. See https://github.com/bevyengine/bevy/issues/23428
+    let gpu_clustering_supported = !(cfg!(target_os = "android") || cfg!(target_abi = "sim"))
         && adapter
             .get_downlevel_capabilities()
             .flags
@@ -237,7 +240,7 @@ enum ViewClusterBuffers {
         cluster_offsets_and_counts: UniformBuffer<GpuClusterOffsetsAndCountsUniform>,
     },
     Storage {
-        clusterable_object_index_lists: UninitBufferVec<u32>,
+        clusterable_object_index_lists: StorageBuffer<GpuClusterableObjectIndexListsStorage>,
         cluster_offsets_and_counts: StorageBuffer<GpuClusterOffsetsAndCountsStorage>,
     },
 }
@@ -596,7 +599,7 @@ impl ViewClusterBindings {
                 cluster_offsets_and_counts,
                 ..
             } => {
-                clusterable_object_index_lists.clear();
+                clusterable_object_index_lists.get_mut().data.clear();
                 cluster_offsets_and_counts.get_mut().data.clear();
             }
         }
@@ -657,11 +660,11 @@ impl ViewClusterBindings {
                 clusterable_object_index_lists.get_mut().data[array_index][component] |=
                     index << (8 * sub_index);
             }
-            ViewClusterBuffers::Storage { .. } => {
-                error!(
-                    "Shouldn't be pushing a clusterable object index from CPU when GPU clustering \
-                     is in use"
-                );
+            ViewClusterBuffers::Storage {
+                clusterable_object_index_lists,
+                ..
+            } => {
+                clusterable_object_index_lists.get_mut().data.push(index);
             }
         }
 
@@ -714,7 +717,10 @@ impl ViewClusterBindings {
                 clusterable_object_index_lists,
                 ..
             } => {
-                clusterable_object_index_lists.add_multiple(elements);
+                clusterable_object_index_lists
+                    .get_mut()
+                    .data
+                    .extend(iter::repeat_n(0, elements));
                 self.n_indices += elements;
             }
         }
@@ -733,7 +739,7 @@ impl ViewClusterBindings {
                 clusterable_object_index_lists,
                 cluster_offsets_and_counts,
             } => {
-                clusterable_object_index_lists.write_buffer(render_device);
+                clusterable_object_index_lists.write_buffer(render_device, render_queue);
                 cluster_offsets_and_counts.write_buffer(render_device, render_queue);
             }
         }
@@ -801,9 +807,7 @@ impl ViewClusterBuffers {
 
     fn storage() -> Self {
         ViewClusterBuffers::Storage {
-            clusterable_object_index_lists: UninitBufferVec::new(
-                BufferUsages::STORAGE | BufferUsages::COPY_DST,
-            ),
+            clusterable_object_index_lists: StorageBuffer::default(),
             cluster_offsets_and_counts: StorageBuffer::default(),
         }
     }

crates/bevy_pbr/src/lib.rs

@@ -29,6 +29,7 @@ mod cluster;
 pub mod contact_shadows;
 #[cfg(feature = "bevy_gltf")]
 mod gltf;
+use bevy_light::cluster::GlobalClusterSettings;
 use bevy_render::sync_component::SyncComponent;
 pub use contact_shadows::{
     ContactShadows, ContactShadowsBuffer, ContactShadowsPlugin, ContactShadowsUniform,
@@ -319,7 +320,13 @@ impl Plugin for PbrPlugin {
                     prepare_lights
                         .in_set(RenderSystems::CreateViews)
                         .after(sort_cameras),
-                    prepare_clusters_for_cpu_clustering.in_set(RenderSystems::PrepareResources),
+                    prepare_clusters_for_cpu_clustering
+                        .in_set(RenderSystems::PrepareResources)
+                        .run_if(
+                            |global_cluster_settings: Res<GlobalClusterSettings>| -> bool {
+                                global_cluster_settings.gpu_clustering.is_none()
+                            },
+                        ),
                 ),
             )
             .init_gpu_resource::<LightMeta>()

examples/mobile/src/lib.rs

@@ -97,7 +97,11 @@ fn setup_scene(
     mut commands: Commands,
     mut meshes: ResMut<Assets<Mesh>>,
     mut materials: ResMut<Assets<StandardMaterial>>,
+    device: Res<bevy::render::renderer::RenderDevice>,
 ) {
+    bevy::log::info!("Configured wgpu adapter Limits: {:#?}", device.limits());
+    bevy::log::info!("Configured wgpu adapter Features: {:#?}", device.features());
+
     // plane
     commands.spawn((
         Mesh3d(meshes.add(Plane3d::default().mesh().size(5.0, 5.0))),