Fixed a null ref exception when no opaque objects are rendered.

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

@@ -377,6 +377,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed lens flare not rendering correctly with TAAU or DLSS.
 - Fixed case where the SceneView don't refresh when using LightExplorer with a running and Paused game (1354129)
 - Fixed wrong ordering in FrameSettings (Normalize Reflection Probes)
+- Fixed a null ref exception when no opaque objects are rendered.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/HDRenderPipeline.RenderGraph.cs

@@ -537,11 +537,16 @@ void SetFinalTarget(RenderGraph renderGraph, HDCamera hdCamera, TextureHandle de
                             using (new ProfilingScope(ctx.cmd, ProfilingSampler.Get(HDProfileId.CopyDepthInTargetTexture)))
                             {
                                 var mpb = ctx.renderGraphPool.GetTempMaterialPropertyBlock();
-                                mpb.SetTexture(HDShaderIDs._InputDepth, data.depthBuffer);
-                                // When we are Main Game View we need to flip the depth buffer ourselves as we are after postprocess / blit that have already flipped the screen
-                                mpb.SetInt("_FlipY", data.flipY ? 1 : 0);
-                                mpb.SetVector(HDShaderIDs._BlitScaleBias, new Vector4(1.0f, 1.0f, 0.0f, 0.0f));
-                                CoreUtils.DrawFullScreen(ctx.cmd, data.copyDepthMaterial, mpb);
+                                RTHandle depth = data.depthBuffer;
+                                // Depth buffer can be invalid if no opaque has been rendered before.
+                                if (depth != null)
+                                {
+                                    mpb.SetTexture(HDShaderIDs._InputDepth, depth);
+                                    // When we are Main Game View we need to flip the depth buffer ourselves as we are after postprocess / blit that have already flipped the screen
+                                    mpb.SetInt("_FlipY", data.flipY ? 1 : 0);
+                                    mpb.SetVector(HDShaderIDs._BlitScaleBias, new Vector4(1.0f, 1.0f, 0.0f, 0.0f));
+                                    CoreUtils.DrawFullScreen(ctx.cmd, data.copyDepthMaterial, mpb);
+                                }
                             }
                         }
                     });