Hd/fix undo environmentlibrary lookdev (#490)

* fix undo redo for environment library

* Update CHANGELOG.md

Co-authored-by: sebastienlagarde <sebastien@unity3d.com>

Author: RSlysz

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

@@ -42,6 +42,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed issue with the shader TransformWorldToHClipDir function computing the wrong result.
 - Fixed division by zero in `V_SmithJointGGX` function.
 - Fixed null reference exception in LookDev when setting the SRP to one not implementing LookDev (case 1245086)
+- Fix LookDev's undo/redo on EnvironmentLibrary (case 1234725)
 
 ### Changed
 - Restored usage of ENABLE_VR to fix compilation errors on some platforms.

com.unity.render-pipelines.core/Editor/LookDev/Context.cs

@@ -264,6 +264,18 @@ internal bool HasLibraryAssetChanged(EnvironmentLibrary environmentLibrary)
 
             return m_EnvironmentLibraryGUID != AssetDatabase.AssetPathToGUID(AssetDatabase.GetAssetPath(environmentLibrary));
         }
+
+        internal void FullReimportEnvironmentLibrary()
+        {
+            if (environmentLibrary == null)
+                return;
+
+            // refresh AssetDatabase in case of undo/redo creating/destructing environment subasset
+            string libraryPath = AssetDatabase.GetAssetPath(environmentLibrary);
+            AssetDatabase.ImportAsset(AssetDatabase.GetAssetPath(environmentLibrary), ImportAssetOptions.DontDownloadFromCacheServer | ImportAssetOptions.ForceSynchronousImport | ImportAssetOptions.ForceUpdate | ImportAssetOptions.ImportRecursive);
+            UpdateEnvironmentLibrary(AssetDatabase.LoadAssetAtPath<EnvironmentLibrary>(libraryPath));
+            EditorUtility.SetDirty(environmentLibrary);
+        }
     }
 
     /// <summary>

com.unity.render-pipelines.core/Editor/LookDev/DisplayWindow.EnvironmentLibrarySidePanel.cs

@@ -463,5 +463,13 @@ void OnFocus()
                 ((IEnvironmentDisplayer)this).Repaint();
             }
         }
+
+        void FullRefreshEnvironmentList()
+        {
+            if (LookDev.currentContext.environmentLibrary != null)
+                LookDev.currentContext.FullReimportEnvironmentLibrary();
+            
+            ((IEnvironmentDisplayer)this).Repaint();
+        }
     }
 }

com.unity.render-pipelines.core/Editor/LookDev/DisplayWindow.cs

@@ -259,9 +259,15 @@ void OnEnable()
 
             ApplyLayout(viewLayout);
             ApplySidePanelChange(layout.showedSidePanel);
+
+            Undo.undoRedoPerformed += FullRefreshEnvironmentList;
         }
 
-        void OnDisable() => OnClosedInternal?.Invoke();
+        void OnDisable()
+        {
+            Undo.undoRedoPerformed -= FullRefreshEnvironmentList;
+            OnClosedInternal?.Invoke();
+        }
 
         void CreateToolbar()
         {

com.unity.render-pipelines.core/Editor/LookDev/EnvironmentLibrary.cs

@@ -32,15 +32,21 @@ public class EnvironmentLibrary : ScriptableObject
         /// <returns>The created Environment</returns>
         public Environment Add()
         {
+            Undo.SetCurrentGroupName("Add Environment");
+            int group = Undo.GetCurrentGroup();
+
             Environment environment = ScriptableObject.CreateInstance<Environment>();
             environment.name = "New Environment";
             Undo.RegisterCreatedObjectUndo(environment, "Add Environment");
 
+            Undo.RecordObject(this, "Add Environment");
             environments.Add(environment);
 
             // Store this new environment as a subasset so we can reference it safely afterwards.
             AssetDatabase.AddObjectToAsset(environment, this);
 
+            Undo.CollapseUndoOperations(group);
+
             // Force save / refresh. Important to do this last because SaveAssets can cause effect to become null!
             EditorUtility.SetDirty(this);
             AssetDatabase.SaveAssets();
@@ -54,11 +60,16 @@ public Environment Add()
         /// <param name="index">Index where to remove Environment</param>
         public void Remove(int index)
         {
+            Undo.SetCurrentGroupName("Remove Environment");
+            int group = Undo.GetCurrentGroup();
+
             Environment environment = environments[index];
             Undo.RecordObject(this, "Remove Environment");
             environments.RemoveAt(index);
             Undo.DestroyObjectImmediate(environment);
 
+            Undo.CollapseUndoOperations(group);
+
             // Force save / refresh
             EditorUtility.SetDirty(this);
             AssetDatabase.SaveAssets();