Fix GC allocations from XR occlusion mesh when using multipass #3077

Author: fabien-unity

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/XR/XRPass.cs

@@ -212,7 +212,7 @@ internal void AddViewInternal(XRView xrView)
         // Must be called after all views have been added to the pass
         internal void UpdateOcclusionMesh()
         {
-            if (isOcclusionMeshSupported && TryGetOcclusionMeshCombinedHashCode(out var hashCode))
+            if (isOcclusionMeshSupported && singlePassEnabled && TryGetOcclusionMeshCombinedHashCode(out var hashCode))
             {
                 if (occlusionMeshCombined == null || hashCode != occlusionMeshCombinedHashCode)
                 {

com.unity.render-pipelines.universal/CHANGELOG.md

@@ -84,6 +84,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Removed Custom.meta which was causing warnings. [case 1314288](https://issuetracker.unity3d.com/issues/urp-warnings-about-missing-metadata-appear-after-installing)
 - Fixed an issue such that it is now posible to enqueue render passes at runtime.
 - Fixed the default background color for previews to use the original color.
+- Fixed GC allocations from XR occlusion mesh when using multipass.
 
 ## [10.2.0] - 2020-10-19
 

com.unity.render-pipelines.universal/Runtime/XR/XRPass.cs

@@ -248,7 +248,7 @@ internal void AddViewInternal(XRView xrView)
         // Must be called after all views have been added to the pass
         internal void UpdateOcclusionMesh()
         {
-            if (isOcclusionMeshSupported && TryGetOcclusionMeshCombinedHashCode(out var hashCode))
+            if (isOcclusionMeshSupported && singlePassEnabled && TryGetOcclusionMeshCombinedHashCode(out var hashCode))
             {
                 if (occlusionMeshCombined == null || hashCode != occlusionMeshCombinedHashCode)
                 {