void UpdatePreviewObjects()
 {
     //if preview scene was destroyed or preview type was changed, reload preview game objects
     if (loadedPreviewType != graphRef.terrainPreviewType)
     {
         TerrainPreviewManager.instance.UpdatePreviewPrefab(previewTypeToPrefabNames[graphRef.terrainPreviewType]);
         loadedPreviewType = graphRef.terrainPreviewType;
     }
 }
        public override void OnEnable()
        {
            graphRef = target as BaseGraph;

            loadedPreviewType = graphRef.terrainPreviewType;

            TerrainPreviewManager.instance.UpdateSceneObjects();

            recenterIcon = Resources.Load <Texture2D>("Icons/ic_recenter");
        }