diff --git a/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs b/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
index 35a1c12be..329032081 100644
--- a/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
+++ b/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
@@ -45,12 +45,12 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 {
 	public static class Object3DTreeBuilder
 	{
-		public static TreeNode BuildTree(IObject3D rootItem, ThemeConfig theme)
+		public static TreeNode BuildTree(IObject3D rootItem, Dictionary<IObject3D, TreeNode> keyValues, ThemeConfig theme)
 		{
-			return AddTree(BuildItemView(rootItem), null, theme);
+			return AddTree(BuildItemView(rootItem), null, keyValues, theme);
 		}
 
-		private static TreeNode AddTree(ObjectView item, TreeNode parent, ThemeConfig theme)
+		private static TreeNode AddTree(ObjectView item, TreeNode parent, Dictionary<IObject3D, TreeNode> keyValues, ThemeConfig theme)
 		{
 			// Suppress MeshWrapper and OperationSource nodes in tree
 			bool shouldCollapseToParent = item.Source is ModifiedMeshObject3D || item.Source is OperationSourceObject3D;
@@ -67,7 +67,9 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					{
 						if (child != null)
 						{
-							AddTree(BuildItemView(child), contextNode, theme);
+							var newNode = AddTree(BuildItemView(child), contextNode, keyValues, theme);
+
+							keyValues?.Add(child, newNode);
 						}
 					}
 				}
diff --git a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
index 027ed03e4..b069eff5b 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
@@ -330,6 +330,8 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 			WorkspaceActions = this.InitWorkspaceActions();
 		}
 
+		private Dictionary<IObject3D, TreeNode> keyValues = new Dictionary<IObject3D, TreeNode>();
+
 		private void RebuildTree()
 		{
 			// Top level selection only - rebuild tree
diff --git a/MatterControlLib/SlicerConfiguration/UIFields/SurfacedEditorPage.cs b/MatterControlLib/SlicerConfiguration/UIFields/SurfacedEditorPage.cs
index 14b7b4dbe..e7a09def4 100644
--- a/MatterControlLib/SlicerConfiguration/UIFields/SurfacedEditorPage.cs
+++ b/MatterControlLib/SlicerConfiguration/UIFields/SurfacedEditorPage.cs
@@ -109,7 +109,7 @@ namespace MatterHackers.MatterControl.SlicerConfiguration
 
 			treeView.ScrollArea.CloseAllChildren();
 
-			var rootNode = Object3DTreeBuilder.BuildTree(selectedItem, theme);
+			var rootNode = Object3DTreeBuilder.BuildTree(selectedItem, null, theme);
 			treeView.AddChild(rootNode);
 			rootNode.TreeView = treeView;