[HDRP] Fix issue with compositor related custom passes

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

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed spacing of UI widgets in the Graphics Compositor (case 1305638).
 - Fixed undo-redo on layered lit editor.
 - Fixed tesselation culling, big triangles using lit tesselation shader would dissapear when camera is too close to them (case 1299116)
+- Fixed issue with compositor related custom passes still active after disabling the compositor (case 1305330)
 
 ### Changed
 - Change the source value for the ray tracing frame index iterator from m_FrameCount to the camera frame count (case 1301356).

com.unity.render-pipelines.high-definition/Runtime/Compositor/AlphaInjection.cs

@@ -27,6 +27,8 @@ public override void Setup()
             var hdrpAsset = HDRenderPipeline.defaultAsset;
             if (hdrpAsset != null)
                 m_Material = CoreUtils.CreateEngineMaterial(hdrpAsset.renderPipelineResources.shaders.alphaInjectionPS);
+
+            name = "AlphaInjection"; // Needed to get a scope name in RenderDoc captures 
         }
 
         public override void Render(CommandBuffer cmd, HDCamera camera, RTHandle source, RTHandle destination)

com.unity.render-pipelines.high-definition/Runtime/Compositor/ChromaKeying.cs

@@ -30,6 +30,8 @@ public override void Setup()
             var hdrpAsset = HDRenderPipeline.defaultAsset;
             if (hdrpAsset != null)
                 m_Material = CoreUtils.CreateEngineMaterial(hdrpAsset.renderPipelineResources.shaders.chromaKeyingPS);
+
+            name = "ChromaKeying"; // Needed to get a scope name in RenderDoc captures 
         }
 
         public override void Render(CommandBuffer cmd, HDCamera camera, RTHandle source, RTHandle destination)

com.unity.render-pipelines.high-definition/Runtime/Compositor/CompositionManager.cs

@@ -63,7 +63,7 @@ public bool enableOutput
                 {
                     m_OutputCamera.enabled = value;
 
-                    // also change the layers
+                    // Aside from the output compositor camera, we also have to change the cameras of the layers
                     foreach (var layer in m_InputLayers)
                     {
                         if (layer.camera && layer.isUsingACameraClone)
@@ -72,11 +72,22 @@ public bool enableOutput
                         }
                         else
                         {
-                            // The target texture was managed by the compositor, reset it so the user can se the camera output
+                            // The target texture was managed by the compositor, reset it so the user can see the camera output
                             if (layer.camera && value == false)
                                 layer.camera.targetTexture = null;
                         }
                     }
+
+                    // Toggle the compositor-related custom passes
+                    var hdPipeline = RenderPipelineManager.currentPipeline as HDRenderPipeline;
+                    if (value)
+                    {
+                        RegisterCustomPasses(hdPipeline);
+                    }
+                    else
+                    {
+                        UnRegisterCustomPasses(hdPipeline);
+                    }
                 }
             }
         }
@@ -186,19 +197,7 @@ bool ValidatePipeline()
                     m_AlphaSupport = AlphaChannelSupport.Rendering;
                 }
 
-                int indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(ChromaKeying).AssemblyQualifiedName);
-                if (indx < 0)
-                {
-                    //Debug.Log("Registering chroma keying pass for the HDRP pipeline");
-                    hdPipeline.asset.beforePostProcessCustomPostProcesses.Add(typeof(ChromaKeying).AssemblyQualifiedName);
-                }
-
-                indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(AlphaInjection).AssemblyQualifiedName);
-                if (indx < 0)
-                {
-                    //Debug.Log("Registering alpha injection pass for the HDRP pipeline");
-                    hdPipeline.asset.beforePostProcessCustomPostProcesses.Add(typeof(AlphaInjection).AssemblyQualifiedName);
-                }
+                RegisterCustomPasses(hdPipeline);
                 return true;
             }
             return false;
@@ -920,5 +919,48 @@ static internal RenderTexture GetClearDepthForStackedCamera(HDCamera hdCamera)
             }
             return null;
         }
+
+        // Register the custom pp passes used by the compositor
+        static internal void RegisterCustomPasses(HDRenderPipeline hdPipeline)
+        {
+            if (hdPipeline == null)
+            {
+                return;
+            }
+
+            // If custom post processes are not registered in the HDRP asset, they are never executed so we have to add them manually
+            int indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(ChromaKeying).AssemblyQualifiedName);
+            if (indx < 0)
+            {
+                hdPipeline.asset.beforePostProcessCustomPostProcesses.Add(typeof(ChromaKeying).AssemblyQualifiedName);
+            }
+
+            indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(AlphaInjection).AssemblyQualifiedName);
+            if (indx < 0)
+            {
+                hdPipeline.asset.beforePostProcessCustomPostProcesses.Add(typeof(AlphaInjection).AssemblyQualifiedName);
+            }
+        }
+
+        // Unregister the custom pp passes used by the compositor
+        static internal void UnRegisterCustomPasses(HDRenderPipeline hdPipeline)
+        {
+            if (hdPipeline == null)
+            {
+                return;
+            }
+
+            int indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(ChromaKeying).AssemblyQualifiedName);
+            if (indx >= 0)
+            {
+                hdPipeline.asset.beforePostProcessCustomPostProcesses.Remove(typeof(ChromaKeying).AssemblyQualifiedName);
+            }
+
+            indx = hdPipeline.asset.beforePostProcessCustomPostProcesses.FindIndex(x => x == typeof(AlphaInjection).AssemblyQualifiedName);
+            if (indx >= 0)
+            {
+                hdPipeline.asset.beforePostProcessCustomPostProcesses.Remove(typeof(AlphaInjection).AssemblyQualifiedName);
+            }
+        }
     }
 }