Hi Ad,

You might give Rhino a try since someone else on this forum said that v5 didn't have these problems:

http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=6201.288

I delete the fragments manually because I have found that a silhouette that ends in the middle of a double-curved surface has a similar artifact where it ends, and that the piece that should be hidden, but is rendered as visible, is joined to the rest of the silhouette curve and so isn't a "short" curve that can be found with a script.

But, if the problem is basically that you want to get closed curves that can be filled, I recommend Adobe Illustrator's LivePaint. It does a good job even when there are little gaps and other problems. Expanding the LivePaint group gives closed shapes that can be stroked, offset, filled with a gradient, etc. You might also try Inkscape's Fill Bounded Areas if you haven't already. The way it works is pretty different from LivePaint and so the results aren't as good, but it might get the job done.

- Peer