[Backport 7.x.x] Fixed asset preview being rendered white because of static lighting sky. (#479)

* Fixed an issue where asset preview could be rendered white because of static lighting sky.

Also fixed an issue where static lighting was not updated when removing the static lighting sky profile.

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

* Update changelog

Author: JulienIgnace-Unity

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

@@ -71,6 +71,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Removed logic in the UI to disable parameters for contact shadows and fog volume components as it was going against the concept of the volume system.
 - Fixed over consumption of GPU memory by the Physically Based Sky.
 - Put more information in Camera background type tooltip and fixed inconsistent exposure behavior when changing bg type.
+- Fixed an issue where asset preview could be rendered white because of static lighting sky.
+- Fixed an issue where static lighting was not updated when removing the static lighting sky profile.
 
 ### 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/Editor/Sky/HDLightingWindowEnvironmentSection.cs

@@ -32,17 +32,13 @@ class SerializedStaticLightingSky
         {
             SerializedObject serializedObject;
             public SerializedProperty skyUniqueID;
-
-            public VolumeProfile volumeProfile
-            {
-                get => (serializedObject.targetObject as StaticLightingSky).profile;
-                set => (serializedObject.targetObject as StaticLightingSky).profile = value;
-            }
+            public SerializedProperty profile;
 
             public SerializedStaticLightingSky(StaticLightingSky staticLightingSky)
             {
                 serializedObject = new SerializedObject(staticLightingSky);
                 skyUniqueID = serializedObject.FindProperty("m_StaticLightingSkyUniqueID");
+                profile = serializedObject.FindProperty("m_Profile");
             }
 
             public void Apply() => serializedObject.ApplyModifiedProperties();
@@ -174,10 +170,10 @@ void DrawGUI()
                 ++EditorGUI.indentLevel;
 
                 //cannot use SerializeProperty due to logic in the property
-                var profile = m_SerializedActiveSceneLightingSky.volumeProfile;
-                var newProfile = EditorGUILayout.ObjectField(EditorGUIUtility.TrTextContent("Profile"), profile, typeof(VolumeProfile), allowSceneObjects: false) as VolumeProfile;
+                var profile = m_SerializedActiveSceneLightingSky.profile.objectReferenceValue;
+                var newProfile = EditorGUILayout.ObjectField(EditorGUIUtility.TrTextContent("Profile"), m_SerializedActiveSceneLightingSky.profile.objectReferenceValue, typeof(VolumeProfile), allowSceneObjects: false) as VolumeProfile;
                 if (profile != newProfile)
-                    m_SerializedActiveSceneLightingSky.volumeProfile = newProfile;
+                    m_SerializedActiveSceneLightingSky.profile.objectReferenceValue = newProfile;
 
                 using (new EditorGUI.DisabledScope(m_SkyClassNames.Count == 1)) // Only "None"
                 {
@@ -204,7 +200,7 @@ void UpdateSkyIntPopupData()
             m_SkyClassNames.Add(new GUIContent("None"));
             m_SkyUniqueIDs.Add(0);
 
-            VolumeProfile profile = m_SerializedActiveSceneLightingSky.volumeProfile;
+            VolumeProfile profile = m_SerializedActiveSceneLightingSky.profile.objectReferenceValue as VolumeProfile;
             if (profile != null)
             {
                 var skyTypesDict = SkyManager.skyTypesDict;

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

@@ -1975,7 +1975,6 @@ AOVRequestData aovRequest
             m_PostProcessSystem.BeginFrame(cmd, hdCamera, this);
 
             ApplyDebugDisplaySettings(hdCamera, cmd);
-            m_SkyManager.UpdateCurrentSkySettings(hdCamera);
 
             SetupCameraProperties(hdCamera, renderContext, cmd);
 
@@ -2755,6 +2754,7 @@ ref HDCullingResults cullingResults
                     hdProbeCullState = HDProbeSystem.PrepareCull(camera);
 
                 // We need to set the ambient probe here because it's passed down to objects during the culling process.
+                skyManager.UpdateCurrentSkySettings(hdCamera);
                 skyManager.SetupAmbientProbe(hdCamera);
 
                 using (new ProfilingScope(null, ProfilingSampler.Get(HDProfileId.CullResultsCull)))