Try to fix occlusion culling (does not seem to be working still)

JMS55 · Jan 18, 2024 · 2a6e022 · 2a6e022
1 parent d2903ac
commit 2a6e022
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Showing 2 changed files with 17 additions and 6 deletions.
diff --git a/crates/bevy_pbr/src/meshlet/cull_meshlets.wgsl b/crates/bevy_pbr/src/meshlet/cull_meshlets.wgsl
@@ -13,8 +13,8 @@
 #import bevy_render::maths::affine_to_square
 
 /// Culls individual meshlets (1 per thread) in two passes (two pass occlusion culling), and outputs a bitmask of which meshlets survived.
-/// 1. The first pass is only frustum culling, on all meshlets that were visible last frame.
-/// 2. The second pass performs both frustum and occlusion culling (using the depth buffer generated from the first pass), on all meshlets that were _not_ visible last frame.
+/// 1. The first pass is only frustum culling, on only the meshlets that were visible last frame.
+/// 2. The second pass performs both frustum and occlusion culling (using the depth buffer generated from the first pass), on all meshlets.
 
 @compute
 @workgroup_size(128, 1, 1)
@@ -30,12 +30,13 @@ fn cull_meshlets(@builtin(global_invocation_id) thread_id: vec3<u32>) {
     let bounding_sphere_center = model * vec4(bounding_sphere.center, 1.0);
     let bounding_sphere_radius = model_scale * bounding_sphere.radius;
 
-    // In the first pass, operate only on the meshlets visible last frame. In the second pass, operate on the opposite set.
-    var meshlet_visible = get_meshlet_previous_occlusion(thread_id.x);
+    // In the first pass, operate only on the meshlets visible last frame. In the second pass, operate on all meshlets.
 #ifdef MESHLET_SECOND_CULLING_PASS
-    meshlet_visible = !meshlet_visible;
-#endif
+    var meshlet_visible = true;
+#else
+    var meshlet_visible = get_meshlet_previous_occlusion(thread_id.x);
     if !meshlet_visible { return; }
+#endif
 
     // Frustum culling
     // TODO: Faster method from https://vkguide.dev/docs/gpudriven/compute_culling/#frustum-culling-function

diff --git a/crates/bevy_pbr/src/meshlet/visibility_buffer_raster_node.rs b/crates/bevy_pbr/src/meshlet/visibility_buffer_raster_node.rs
@@ -118,6 +118,11 @@ impl Node for MeshletVisibilityBufferRasterPassNode {
             write_index_buffer_pipeline,
             write_index_buffer_workgroups,
         );
+        render_context.command_encoder().clear_buffer(
+            &meshlet_view_resources.occlusion_buffer,
+            0,
+            None,
+        );
         raster_pass(
             true,
             render_context,
@@ -214,6 +219,11 @@ impl Node for MeshletVisibilityBufferRasterPassNode {
                 write_index_buffer_pipeline,
                 write_index_buffer_workgroups,
             );
+            render_context.command_encoder().clear_buffer(
+                &meshlet_view_resources.occlusion_buffer,
+                0,
+                None,
+            );
             raster_pass(
                 true,
                 render_context,