Burrman, I started to go that route, but got stymied and went in another direction when I couldn't figure out what operation to use to generate those points. I could come up with intersection lines using a sectioning plane, but I'd rather use points straight off of the original 3D curves, as you show. How did you generate the points off of curves intersecting a plane? Once that piece falls into place, I think I'll have the thing sewed up.

Luke