Add caching review model in Animation window

#2508

Source/Editor/Windows/Assets/AnimationWindow.cs

@@ -80,6 +80,7 @@ namespace FlaxEditor.Windows.Assets
             private AnimationWindow Window;
             private Animation Asset;
             private ModelImportSettings ImportSettings = new ModelImportSettings();
+            private bool EnablePreviewModelCache = true;
 
             [EditorDisplay("Preview"), NoSerialize, AssetReference(true), Tooltip("The skinned model to preview the animation playback.")]
             public SkinnedModel PreviewModel
@@ -134,6 +135,15 @@ namespace FlaxEditor.Windows.Assets
                         value.WaitForLoaded(500);
                         Window._preview.ViewportCamera.SetArcBallView(Window._preview.PreviewActor.Sphere);
                     }
+
+                    if (EnablePreviewModelCache)
+                    {
+                        var customDataName = Window.GetPreviewModelCacheName();
+                        if (value)
+                            Window.Editor.ProjectCache.SetCustomData(customDataName, value.ID.ToString());
+                        else
+                            Window.Editor.ProjectCache.RemoveCustomData(customDataName);
+                    }
                 }
             }
 
@@ -142,6 +152,7 @@ namespace FlaxEditor.Windows.Assets
                 // Link
                 Window = window;
                 Asset = window.Asset;
+                EnablePreviewModelCache = true;
 
                 // Try to restore target asset import options (useful for fast reimport)
                 Editor.TryRestoreImportOptions(ref ImportSettings.Settings, window.Item.Path);
@@ -150,6 +161,7 @@ namespace FlaxEditor.Windows.Assets
             public void OnClean()
             {
                 // Unlink
+                EnablePreviewModelCache = false;
                 PreviewModel = null;
                 Window = null;
                 Asset = null;
@@ -287,12 +299,23 @@ namespace FlaxEditor.Windows.Assets
             UpdateToolstrip();
         }
 
+        private string GetPreviewModelCacheName()
+        {
+            return _asset.ID + ".PreviewModel";
+        }
+
         /// <inheritdoc />
         protected override void OnAssetLoaded()
         {
             _properties.OnLoad(this);
             _propertiesPresenter.BuildLayout();
             ClearEditedFlag();
+            if (!_initialPreviewModel && 
+                Editor.ProjectCache.TryGetCustomData(GetPreviewModelCacheName(), out string str) && 
+                Guid.TryParse(str, out var id))
+            {
+                _initialPreviewModel = FlaxEngine.Content.LoadAsync<SkinnedModel>(id);
+            }
             if (_initialPreviewModel)
             {
                 _properties.PreviewModel = _initialPreviewModel;