Hi,
Is there some function in RhinoCommon like the WeldVertices command?
http://docs.mcneel.com/rhino/5/help/en-us/commands/weld.htm
thanks.
EDIT: Thought I had too look into the vertices but its weld:
Dim ad As Geometry.Mesh = m.Mesh
ad.Weld(RhinoMath.ToRadians(90))