Solari: More examples, fix emissive (#22295)

* Add a small profiling overlay to the Solari example that times
different parts of Solari's GPU work (DLSS-RR not added because wgpu
timestamps aren't working correctly with wgpu_hal work, I need to fix
that as a separate thing)
* Add a many-lights stress test to the Solari example (100 lights)
inspired by https://x.com/Roystoncinemo/status/1841917611833229411.
Currently somewhat unusable, but this will ideally be a bigger focus for
Solari 0.19.
* Changed emissive to have exposure applied, as if
`emissive_exposure_weight` was always set to 1.0 (StandardMaterial
defaults to 0.0 which I'm not convinced is a good idea, but that's a
separate topic). If we didn't do this, the emissive meshes would render
as insanely bright white to the point of overflowing the texture and
breaking DLSS-RR. I think the new behavior is more what people expect to
happen, and matches the pathtracer result now.
<img width="3206" height="1875" alt="image"
src="https://github.com/user-attachments/assets/af3990d6-ae2d-4520-a7cd-f04041685152"
/>

---------

Co-authored-by: Chris Biscardi <[email protected]>
Co-authored-by: Alice Cecile <[email protected]>

Author: 3 people

crates/bevy_solari/src/realtime/node.rs

@@ -240,7 +240,6 @@ impl ViewNode for SolariLightingNode {
             label: Some("solari_lighting"),
             timestamp_writes: None,
         });
-        let pass_span = diagnostics.pass_span(&mut pass, "solari_lighting");
 
         let dx = solari_lighting_resources.view_size.x.div_ceil(8);
         let dy = solari_lighting_resources.view_size.y.div_ceil(8);
@@ -262,12 +261,16 @@ impl ViewNode for SolariLightingNode {
             pass.dispatch_workgroups(dx, dy, 1);
         }
 
+        let d = diagnostics.time_span(&mut pass, "solari_lighting/presample_light_tiles");
         pass.set_pipeline(presample_light_tiles_pipeline);
         pass.set_push_constants(
             0,
             bytemuck::cast_slice(&[frame_index, solari_lighting.reset as u32]),
         );
         pass.dispatch_workgroups(LIGHT_TILE_BLOCKS as u32, 1, 1);
+        d.end(&mut pass);
+
+        let d = diagnostics.time_span(&mut pass, "solari_lighting/world_cache");
 
         pass.set_bind_group(2, &bind_group_world_cache_active_cells_dispatch, &[]);
 
@@ -301,6 +304,10 @@ impl ViewNode for SolariLightingNode {
             0,
         );
 
+        d.end(&mut pass);
+
+        let d = diagnostics.time_span(&mut pass, "solari_lighting/direct_lighting");
+
         pass.set_pipeline(di_initial_and_temporal_pipeline);
         pass.set_push_constants(
             0,
@@ -315,6 +322,10 @@ impl ViewNode for SolariLightingNode {
         );
         pass.dispatch_workgroups(dx, dy, 1);
 
+        d.end(&mut pass);
+
+        let d = diagnostics.time_span(&mut pass, "solari_lighting/diffuse_indirect_lighting");
+
         pass.set_pipeline(gi_initial_and_temporal_pipeline);
         pass.set_push_constants(
             0,
@@ -329,14 +340,16 @@ impl ViewNode for SolariLightingNode {
         );
         pass.dispatch_workgroups(dx, dy, 1);
 
+        d.end(&mut pass);
+
+        let d = diagnostics.time_span(&mut pass, "solari_lighting/specular_indirect_lighting");
         pass.set_pipeline(specular_gi_pipeline);
         pass.set_push_constants(
             0,
             bytemuck::cast_slice(&[frame_index, solari_lighting.reset as u32]),
         );
         pass.dispatch_workgroups(dx, dy, 1);
-
-        pass_span.end(&mut pass);
+        d.end(&mut pass);
 
         Ok(())
     }

crates/bevy_solari/src/realtime/restir_di.wgsl

@@ -96,9 +96,9 @@ fn spatial_and_shade(@builtin(global_invocation_id) global_id: vec3<u32>) {
     let brdf = evaluate_brdf(surface.world_normal, wo, merge_result.wi, surface.material);
 
     var pixel_color = merge_result.selected_sample_radiance * combined_reservoir.unbiased_contribution_weight;
-    pixel_color *= view.exposure;
     pixel_color *= brdf;
     pixel_color += surface.material.emissive;
+    pixel_color *= view.exposure;
     textureStore(view_output, global_id.xy, vec4(pixel_color, 1.0));
 }