[7.x.x Backport] Fix issue with ambient probe not being correct with OnEnable/OnDemand probes (#317)

* render until ambient probe is ready

* remove comment

* changelog

Author: FrancescoC-unity

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

@@ -629,6 +629,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Added a fix script to handle the warning 'referenced script in (GameObject 'SceneIDMap') is missing'
 - Fix Wizard load when none selected for RenderPipelineAsset
 - Fixed issue with unclear naming of debug menu for decals.
+- Fixed issue with reflection probes in realtime time mode with OnEnable baking having wrong lighting with sky set to dynamic (case 1238047).
 
 ### Changed
 - Color buffer pyramid is not allocated anymore if neither refraction nor distortion are enabled

com.unity.render-pipelines.high-definition/Runtime/Lighting/Reflection/HDProbe.cs

@@ -428,6 +428,13 @@ public virtual void PrepareCulling() { }
         /// </summary>
         public void RequestRenderNextUpdate() => m_WasRenderedSinceLastOnDemandRequest = false;
 
+        // Forces the re-rendering for both OnDemand and OnEnable
+        internal void ForceRenderingNextUpdate()
+        {
+            m_WasRenderedSinceLastOnDemandRequest = false;
+            wasRenderedAfterOnEnable = false;
+        }
+
         void UpdateProbeName()
         {
             // TODO: ask if this is ok:

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

@@ -1620,6 +1620,14 @@ ref _cullingResults
                             continue;
                         }
 
+                        // HACK! We render the probe until we know the ambient probe for the associated sky context is ready.
+                        // For one-off rendering the dynamic ambient probe will be set to black until they are not processed, leading to faulty rendering.
+                        // So we enqueue another rendering and then we will not set the probe texture until we have rendered with valid ambient probe.
+                        if (!m_SkyManager.HasSetValidAmbientProbe(hdCamera))
+                        {
+                            visibleProbe.ForceRenderingNextUpdate();
+                        }
+
                         hdCamera.parentCamera = parentCamera; // Used to inherit the properties of the view
 
                         HDAdditionalCameraData hdCam;
@@ -1666,26 +1674,30 @@ ref _cullingResults
                             // TODO: store DecalCullResult
                         };
 
-                        // As we render realtime texture on GPU side, we must tag the texture so our texture array cache detect that something have change
-                        visibleProbe.realtimeTexture.IncrementUpdateCount();
-
-                        if (cameraSettings.Count > 1)
+                        if (m_SkyManager.HasSetValidAmbientProbe(hdCamera))
                         {
-                            var face = (CubemapFace)j;
-                            request.target = new RenderRequest.Target
+                            // As we render realtime texture on GPU side, we must tag the texture so our texture array cache detect that something have change
+                            visibleProbe.realtimeTexture.IncrementUpdateCount();
+
+                            if (cameraSettings.Count > 1)
                             {
-                                copyToTarget = visibleProbe.realtimeTexture,
-                                face = face
-                            };
-                        }
-                        else
-                        {
-                            request.target = new RenderRequest.Target
+                                var face = (CubemapFace)j;
+                                request.target = new RenderRequest.Target
+                                {
+                                    copyToTarget = visibleProbe.realtimeTexture,
+                                    face = face
+                                };
+                            }
+                            else
                             {
-                                id = visibleProbe.realtimeTexture,
-                                face = CubemapFace.Unknown
-                            };
+                                request.target = new RenderRequest.Target
+                                {
+                                    id = visibleProbe.realtimeTexture,
+                                    face = CubemapFace.Unknown
+                                };
+                            }
                         }
+
                         renderRequests.Add(request);
 
 

com.unity.render-pipelines.high-definition/Runtime/Sky/SkyManager.cs

@@ -413,6 +413,24 @@ internal SphericalHarmonicsL2 GetAmbientProbe(HDCamera hdCamera)
             return GetAmbientProbe(hdCamera.lightingSky);
         }
 
+        internal bool HasSetValidAmbientProbe(HDCamera hdCamera)
+        {
+            SkyAmbientMode ambientMode = hdCamera.volumeStack.GetComponent<VisualEnvironment>().skyAmbientMode.value;
+            if (ambientMode == SkyAmbientMode.Static)
+                return true;
+
+            if (hdCamera.skyAmbientMode == SkyAmbientMode.Dynamic && hdCamera.lightingSky != null &&
+                hdCamera.lightingSky.IsValid() && IsCachedContextValid(hdCamera.lightingSky))
+            {
+                ref CachedSkyContext cachedContext = ref m_CachedSkyContexts[hdCamera.lightingSky.cachedSkyRenderingContextId];
+                var renderingContext = cachedContext.renderingContext;
+                return renderingContext.ambientProbeIsReady;
+            }
+
+            return false;
+
+        }
+
         internal void SetupAmbientProbe(HDCamera hdCamera)
         {
             // Working around GI current system

com.unity.render-pipelines.high-definition/Runtime/Sky/SkyRenderingContext.cs

@@ -14,6 +14,8 @@ internal class SkyRenderingContext
         public CubemapArray skyboxBSDFCubemapArray { get; private set; }
         public bool supportsConvolution { get; private set; } = false;
 
+        internal bool ambientProbeIsReady = false;
+
         public SkyRenderingContext(int resolution, int bsdfCount, bool supportsConvolution, SphericalHarmonicsL2 ambientProbe, string name)
         {
             m_AmbientProbe = ambientProbe;
@@ -71,6 +73,8 @@ public void OnComputeAmbientProbeDone(AsyncGPUReadbackRequest request)
                         m_AmbientProbe[channel, coeff] = result[channel * 9 + coeff];
                     }
                 }
+
+                ambientProbeIsReady = true;
             }
         }
     }