Hi John, I've been looking at your O there and I haven't been able to quite figure out what the problem is.

It seems to be that the solid offsetter is what is getting messed up though - if you do just a regular offset (not inset), you can see that it makes a pretty messed up result.

Producing an offset is one stage of the inset command and so if offsetting is messed up, certainly inset is not going to work right either.

It doesn't look like it should be a difficult case, but one guess I have right now is that possibly even though the O is a single segment, it may have a very slight tangent deviation between the start and end where it comes together. That may be making the solid offsetter doing an attempt to make an extension of those edges when they are offset and it's probably getting confused with then trying to intersect those extensions that are just barely grazing each other.

Doing a Rebuild on the curves of the O before creating a solid from it and deforming it may help with this issue as well since it will also true up things that are nearly tangent into being exactly tangent and that will probably help avoid the problems with the offset trying to extend it later on.

That's still kind of a guess but I've seen some similar situations before that were running into that kind of problem with extensions on things with just very slightly non-tangent edges.

Do you happen to have the original object before it was deformed?

- Michael