diff --git a/PartPreviewWindow/View3D/BedMeshGenerator.cs b/PartPreviewWindow/View3D/BedMeshGenerator.cs
index 7a941f4ff..7c6b261e7 100644
--- a/PartPreviewWindow/View3D/BedMeshGenerator.cs
+++ b/PartPreviewWindow/View3D/BedMeshGenerator.cs
@@ -122,7 +122,7 @@ namespace MatterHackers.MatterControl
 						{
 							foreach (Face face in printerBed.Faces)
 							{
-								if (face.normal.z > 0)
+								if (face.Normal.z > 0)
 								{
 									face.SetTexture(0, bedplateImage);
 									foreach (FaceEdge faceEdge in face.FaceEdges())
diff --git a/PartPreviewWindow/View3D/GeneralObject3DEditor.cs b/PartPreviewWindow/View3D/GeneralObject3DEditor.cs
index d4de1987f..d9891548f 100644
--- a/PartPreviewWindow/View3D/GeneralObject3DEditor.cs
+++ b/PartPreviewWindow/View3D/GeneralObject3DEditor.cs
@@ -32,6 +32,7 @@ using MatterHackers.Agg;
 using MatterHackers.Agg.UI;
 using MatterHackers.DataConverters3D;
 using MatterHackers.Localizations;
+using MatterHackers.PolygonMesh;
 
 namespace MatterHackers.MatterControl.PartPreviewWindow
 {
@@ -91,6 +92,11 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 			holeBehaviorButton.Click += (s, e) =>
 			{
 				item.OutputType = PrintOutputTypes.Hole;
+				if(item.Mesh != null)
+				{
+					item.Mesh.FaceBspTree = FaceBspTree.Create(item.Mesh);
+				}
+
 				view3DWidget.Invalidate();
 			};
 
diff --git a/PartPreviewWindow/View3D/MeshViewerWidget.cs b/PartPreviewWindow/View3D/MeshViewerWidget.cs
index ab9149465..0a36713f3 100644
--- a/PartPreviewWindow/View3D/MeshViewerWidget.cs
+++ b/PartPreviewWindow/View3D/MeshViewerWidget.cs
@@ -413,25 +413,48 @@ namespace MatterHackers.MeshVisualizer
 								FaceEdge firstFaceEdge = meshEdge.firstFaceEdge;
 								FaceEdge nextFaceEdge = meshEdge.firstFaceEdge.radialNextFaceEdge;
 								// find out if one face is facing the camera and one is facing away
-								var vertexPosition = World.GetScreenSpace(Vector3.Transform(firstFaceEdge.FirstVertex.Position, renderData.Matrix));
-								var firstNormal = World.GetScreenSpace(Vector3.Transform(firstFaceEdge.FirstVertex.Position + firstFaceEdge.ContainingFace.normal, renderData.Matrix));
-								var nextNormal = World.GetScreenSpace(Vector3.Transform(firstFaceEdge.FirstVertex.Position + nextFaceEdge.ContainingFace.normal, renderData.Matrix));
+								var worldVertexPosition = Vector3.Transform(firstFaceEdge.FirstVertex.Position, renderData.Matrix);
+								var worldFirstNormal = Vector3.TransformNormal(firstFaceEdge.ContainingFace.Normal, renderData.Matrix).GetNormal();
+								var worldNextNormal = Vector3.TransformNormal(nextFaceEdge.ContainingFace.Normal, renderData.Matrix).GetNormal();
 
-								var firstTowards = (firstNormal - vertexPosition).z < 0;
-								var nextTowards = (nextNormal - vertexPosition).z < 0;
+								var screenVertexPosition = World.GetScreenSpace(worldVertexPosition);
+								var screenFirstNormalEnd = World.GetScreenSpace(worldVertexPosition + worldFirstNormal);
+								var screenNextNormalEnd = World.GetScreenSpace(worldVertexPosition + worldNextNormal);
+
+								var firstTowards = (screenFirstNormalEnd - screenVertexPosition).z < 0;
+								var nextTowards = (screenNextNormalEnd - screenVertexPosition).z < 0;
 
 								if (firstTowards != nextTowards)
 								{
 									var transformed1 = Vector3.Transform(meshEdge.VertexOnEnd[0].Position, renderData.Matrix);
 									var transformed2 = Vector3.Transform(meshEdge.VertexOnEnd[1].Position, renderData.Matrix);
 
-									for (int i = 0; i < 3; i++)
-									{
-										GLHelper.Render3DLineNoPrep(frustum, World, transformed1, transformed2, RGBA_Bytes.White, selectionHighlightWidth);
-									}
+									GLHelper.Render3DLineNoPrep(frustum, World, transformed1, transformed2, RGBA_Bytes.White, selectionHighlightWidth);
 								}
 							}
 						}
+
+						// render debug normals
+						bool renderNormal = false;
+						if (renderNormal)
+						{
+							foreach (var face in renderData.Mesh.Faces)
+							{
+								int vertexCount = 0;
+								Vector3 faceCenter = Vector3.Zero;
+								foreach (var vertex in face.Vertices())
+								{
+									faceCenter += vertex.Position;
+									vertexCount++;
+								}
+								faceCenter /= vertexCount;
+
+								var transformed1 = Vector3.Transform(faceCenter, renderData.Matrix);
+								var normal = Vector3.TransformNormal(face.Normal, renderData.Matrix).GetNormal();
+
+								GLHelper.Render3DLineNoPrep(frustum, World, transformed1, transformed1 + normal, RGBA_Bytes.Red, selectionHighlightWidth);
+							}
+						}
 					}
 					else // just render the bounding box
 					{
diff --git a/PartPreviewWindow/View3D/View3DWidget.cs b/PartPreviewWindow/View3D/View3DWidget.cs
index 6f0051a48..1dd5a0526 100644
--- a/PartPreviewWindow/View3D/View3DWidget.cs
+++ b/PartPreviewWindow/View3D/View3DWidget.cs
@@ -2557,7 +2557,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 							// change the color to be the right thing
 							GLMeshTrianglePlugin glMeshPlugin = GLMeshTrianglePlugin.Get(meshRenderData.Mesh, (faceEdge) =>
 							{
-								Vector3 normal = faceEdge.ContainingFace.normal;
+								Vector3 normal = faceEdge.ContainingFace.Normal;
 								normal = Vector3.TransformVector(normal, meshRenderData.Matrix).GetNormal();
 								VertexColorData colorData = new VertexColorData();
 
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index 85e2df1ab..09c71c0d0 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit 85e2df1ab9985343453f3e0753c1e1fa3f3e19cc
+Subproject commit 09c71c0d02dfa3af6871fe18f57c4fd07a104e61