Hi,

Is there a way to clean-up self intersecting polygons? I'm getting them after a PolyExtrude with a negative inset on a closed curve.

thanks,

Jeroen

I should probably add that the curve is a concave polygon and that I'm only keeping the sides (not the front or back faces). It is obvious that edges will eventually self intersect when the negative inset is large enough. I hope that there is a way to prevent or fix these.

The following link shows a lightwave script (Rasp 008 in the list) which does an edge collapse that I think would solve my problem. The page shows some images that help clarify my issue.

http://www.pictrix.jp/lw/index2.html [pictrix.jp]

Hello,

Make sure that you are using the “Inset” parameter instead of a scale in the local XY plane – it usually behaves much better on concave polys. Having said that, there will still be cases where you get that corssing problem. I wasn't really able to read the linked page, but you can do similar things (I believe) with a PolySplit (to connect the two crossing edges where they cross) and then an EdgeCollapse.

Also, you may want to check out Extrude SOP, it is older than PolyExtrude, but I believe it does protect from these crossing edges (though it is a little trickier to use).

Hope that helps,
George.

Looks a bit like you could do the same thing by just fusing the offending points using a very large fuse radius. no? Though you would probably need to adjust the position after the fuse since the points wouldn't land up on the insection point.
I think also that George is right the older extrude sop does a much job of not creating the problem in the first place. If you give it a shape like the ones in the lightwave example it doesn't create self intersection.

Cool, Extrude's results are indeed much better in terms of intersections.

thanks for your help!