Addressing Scrolling Object Collection related issues

Author: MaxWang-MS

Assets/MRTK/Core/Utilities/Rendering/MaterialInstance.cs

@@ -86,7 +86,7 @@ public void ReleaseMaterial(Object owner, bool autoDestroy = true)
 
             if (autoDestroy && materialOwners.Count == 0)
             {
-                DestorySafe(this);
+                DestroySafe(this);
 
                 // OnDestroy not called on inactive objects
                 if (!gameObject.activeInHierarchy)
@@ -295,7 +295,7 @@ private static void DestroyMaterials(Material[] materials)
             {
                 for (var i = 0; i < materials.Length; ++i)
                 {
-                    DestorySafe(materials[i]);
+                    DestroySafe(materials[i]);
                 }
             }
         }
@@ -321,7 +321,7 @@ private static bool HasValidMaterial(Material[] materials)
             return false;
         }
 
-        private static void DestorySafe(UnityEngine.Object toDestroy)
+        private static void DestroySafe(Object toDestroy)
         {
             if (toDestroy != null)
             {

Assets/MRTK/Core/Utilities/StandardShader/ClippingPrimitive.cs

@@ -160,7 +160,7 @@ public void RemoveRenderer(Renderer _renderer)
             }
         }
 
-        private void RemoveRenderer(int index)
+        private void RemoveRenderer(int index, bool autoDestroyMaterial = true)
         {
             Renderer _renderer = renderers[index];
 
@@ -181,21 +181,21 @@ private void RemoveRenderer(int index)
                 var materialInstance = _renderer.GetComponent<MaterialInstance>();
                 if (materialInstance != null)
                 {
-                    materialInstance.ReleaseMaterial(this);
+                    materialInstance.ReleaseMaterial(this, autoDestroyMaterial);
                 }
             }
         }
 
         /// <summary>
         /// Removes all renderers in the list of objects this clipping primitive clips.
         /// </summary>
-        public void ClearRenderers()
+        public void ClearRenderers(bool autoDestroyMaterial = true)
         {
             if (renderers != null)
             {
                 while (renderers.Count != 0)
                 {
-                    RemoveRenderer(renderers.Count - 1);
+                    RemoveRenderer(renderers.Count - 1, autoDestroyMaterial);
                 }
             }
         }
@@ -314,9 +314,12 @@ protected virtual void UpdateRenderers()
             for (int i = renderers.Count - 1; i >= 0; --i)
             {
                 var _renderer = renderers[i];
-                if (Application.isPlaying && _renderer == null)
+                if (_renderer == null)
                 {
-                    RemoveRenderer(i);
+                    if (Application.isPlaying)
+                    {
+                        RemoveRenderer(i);
+                    }
                     continue;
                 }
 

Assets/MRTK/SDK/Features/UX/Scripts/ScrollingObjectCollection/ScrollingObjectCollection.cs

@@ -1183,7 +1183,22 @@ private void OnDisable()
             CoreServices.InputSystem?.UnregisterHandler<IMixedRealityTouchHandler>(this);
             CoreServices.InputSystem?.UnregisterHandler<IMixedRealityPointerHandler>(this);
 
+            // Currently in editor duplicating prefab GameObject containing both TMP and non-TMP children inside the Scrolling Object Collection container causes material life cycle management issues
+            // https://github.com/microsoft/MixedRealityToolkit-Unity/issues/9481
+            // Thus we do not automatically destroy material controlled by Material Instance if the OnDisable comes from pasting in editor
+#if UNITY_EDITOR
+            if (!Application.isPlaying)
+            {
+                bool? isCalledFromPastingGameObject = new System.Diagnostics.StackFrame(1)?.GetMethod()?.Name?.Contains("Paste");
+                RestoreContentVisibility(!isCalledFromPastingGameObject.GetValueOrDefault());
+            }
+            else
+            {
+                RestoreContentVisibility();
+            }
+#else
             RestoreContentVisibility();
+#endif
 
             if (useOnPreRender && cameraMethods != null)
             {
@@ -1643,9 +1658,9 @@ private void RemoveRenderersFromClippingObject(List<Renderer> renderers)
         /// <summary>
         /// Removes all renderers currently being clipped by the clipping box
         /// </summary>
-        private void ClearClippingBox()
+        private void ClearClippingBox(bool autoDestroyMaterial = true)
         {
-            ClipBox.ClearRenderers();
+            ClipBox.ClearRenderers(autoDestroyMaterial);
         }
 
         /// <summary>
@@ -1897,9 +1912,9 @@ private void ResetScrollOffset()
         /// <summary>
         /// All inactive content objects and colliders are reactivated and renderers are unclipped.
         /// </summary>
-        private void RestoreContentVisibility()
+        private void RestoreContentVisibility(bool autoDestroyMaterial = true)
         {
-            ClearClippingBox();
+            ClearClippingBox(autoDestroyMaterial);
             ManageVisibility(true);
         }