Hi Micha - one other note on "butterfly points" - maybe these could also happen if the mesh that MoI exported did not get completely welded.

One thing you may want to look at is if your base object is of very small or very large size in units. I mean for example if your entire model is something like 0.03 units across, or 100000 units across, either of those can cause some problems.

If you try to get your model to be a more consistent size more like 10 units across instead of very large or very small that may help various things work more smoothly and may have points welded better.

Just another possible thing to look at anyway.


Probably a lack of welding is what would be generating your butterfly points in most cases rather than a completely unsuitable modeled topology. Another big thing to check though is whether your object is a closed solid or not, if it is not a solid then some edges of it are open edges which will then generate open border edges which is part of what makes a "butterfly point". So that is another big thing to check for.


Objects of a very small or large size can be harder to get automatically joined into a solid when imported from IGES or something like that.


- Michael