[9.x.x] Fix Microshadow not working properly with LightLayers enabled in deferred #522

Author: sebastienlagarde

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -88,6 +88,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed error when undo a Reflection Probe removal in a prefab instance. (case 1244047)
 - Fixed various multi-editing issues when changing Emission parameters.
 - Fixed issue that prevented cubemap thumbnails from rendering (only on D3D11 and Metal).
+- Fixed Microshadow not working correctly in deferred with LightLayers
 
 ### Changed
 - Rejecting history for ray traced reflections based on a threshold evaluated on the neighborhood of the sampled history.

com.unity.render-pipelines.high-definition/Runtime/Material/Lit/Lit.hlsl

@@ -195,11 +195,8 @@ float GetAmbientOcclusionForMicroShadowing(BSDFData bsdfData)
 {
     float sourceAO;
 #if (SHADERPASS == SHADERPASS_DEFERRED_LIGHTING)
-    // Note: In deferred pass we don't have space in GBuffer to store ambientOcclusion unless LIGHT_LAYERS is enabled
-    // so we use specularOcclusion instead
-    // The define LIGHT_LAYERS only exist for the GBuffer and the Forward pass. To avoid to add another
-    // variant to deferred.compute, we use dynamic branching instead with _EnableLightLayers.
-    sourceAO = _EnableLightLayers ? bsdfData.ambientOcclusion : bsdfData.specularOcclusion;
+    // Note: In deferred pass we don't have space in GBuffer to store ambientOcclusion so we use specularOcclusion instead
+    sourceAO = bsdfData.specularOcclusion;
 #else
     sourceAO = bsdfData.ambientOcclusion;
 #endif