Shading problem with vertices weld

Rhino Windows Hardware
1

Hi all,

I encountered a problem with vertices weld. In GH i build a wall with clean mesh geometry. It’s build using cuts at the window sides and deleting the window openings. This way it’s optimized for export to Unreal.
Thing is that all the vertices are unwelded. When doing a weld vertices operation I get shading problems which also exports to Blender/3DsMax trough FBX and is visible in my V-Ray renders. When I export the unwelded version to 3DsMax trough FBX its possible to weld the vertices there. 3DsMax doesn’t give these shading problems. Is this a bug in Rhino 6, or am I doing something wrong?

Greetings, Jakob.

Geometry
Geometry625×578 111 KB

Rendered without veritces weld
Rendered without veritces weld625×578 23.3 KB

Rendered after veritces weld
Rendered after veritces weld625×578 84.3 KB

2

Hi @pixual, you would ideally pass a face normal angle tolerance for determining which edges to weld. So the edges between flat areas would be welded and the 90 degree edges around the window holes left unwelded. In RhinoCommon calling Mesh.Weld(double angleToleranceRadians) with a tolerance around 0.17 (it’s about 10 degrees) would do that.