If I have an arc sketched on the top plane, sketched left-to-right such that the first arc endpoint is to the left and the 2nd is to the right, and extrude it as a surface in the +Y direction, it will untrim just fine
If instead I extrude it in the -Y direction, only half of the surface will untrim.
If I reverse the sketching direction, such that the first arc end point is to the right, and again extrude it as a surface in the -Y direction, it won't untrim at all.
I expect untrim to do better and worse at times with tolerant NURBS geometry. But I was very surprised that it can't reliably handle a simple analytic (cylindrical) surface. Can anyone venture a guess as to why? I'm curious if this is a solidworks issue or a parasolid kernel issue.
