Hi Pilou, what type of alarm bell would you expect?

I guess the geometry library does not understand that an error has occured, something inside of it just gets confused about "inside" versus "outside" for that top face. This is often something that gets easily messed up when trim curve pieces end up in intersecting loops.

I guess I could detect that the original object was a fully closed solid, but the new one is not fully closed, and then not create that object.

But it is probably more useful to create the object even if it is broken in some areas, because you can then break it into separate parts and trim some of those fillets, and maybe be able to salvage a good final result by using some of those pieces...

Doing nothing isn't quite as useful. I guess what would be ideal would be to allow the object to be created, but to report that there was a possible error in it. But I haven't yet found a good location in the UI to communicate this type of feedback from MoI back to you. Do you have any ideas?

- Michael