Brep CreateFromSweep Fails for shallow Triangles

Good Morning All,

Using Brep.CreateFromSweep (in C#) I try to sweep the little blue line around the inside of the triangle I get a rather strange result - anyone know how to avoid this? I was expecting the sweep to stay inside the triangle.
Brep.CreateFromSweep(curve, line, true, 0.0001)

I have explored the SweepOneRail but had other problems with that and “Note, this class has been superseded by the Rhino.Geometry.Brep.CreateFromSweep static functions.”

BrepSweepFail.3dm (46.7 KB)


Either move the seam of the closed curve to where it intersects the cross section, or move the cross section to the start of the curve.

– Dale