Hi Larry, thanks for sending it in, it is indeed a different bug than the other one. Actually it's 2 bugs, the first one is in display mesh generation and the second one was in the same area of code as that previous bug but in a slightly different thing.

The display mesh bug is the one that looks like this:


So the problem is if this edge here is not refined with enough points:



It's going to cross over the inner boundary like this:



That one will go away during mesh export if you use a tight enough angle like 6 degrees or lower. This one is pretty difficult to fix because it would involve testing a lot of edges against each other to see if they intersect or not which would be a major performance degradation in display mesh generation. In the future maybe I could try something like only do that additional testing if the mesh was damaged. But it's basically a display artifact and the actual model is ok there and will also be ok during mesh export using a tight enough angle. Even without a tight enough angle the export mesh doesn't leak out so badly and the damage is contained just to that small area. So I'm not expecting to fix this one in v4.

All the other messed up areas are from the 2nd bug which I've fixed for the next v4 beta so in the next beta the export will look like this:




> I promise I'll stop bugging you afterwards :)

:) It's not any problem at all in fact I really appreciate you sending them in so I can get them fixed in v4! If you run into any more please go ahead and send them. If it's more convenient you can e-mail them to me at moi@moi3d.com .

MoI itself does not happen to write out .3dm files with the thing that involves these bugs, that's why they've stayed hidden for quite a while.

Thanks, - Michael