Hi Michael,

> Hi PaQ, this looks like one of those things that gets corrected automatically when the file is read back in, because when I open your file over here it seems to be all ok now.

Something to do with the viewport settings maybe ? Because here I still have the problem if I reopen the file.



> Do you happen to have a version of this before the filleting, so I can try to reproduce the error by applying the fillet?

No I don't, but I will reproduce the construction here.

I'm not sure if I was clear enough, can you fillet any little holes from the model without any problem ?

Hi PaQ - thanks, I can repeat it now in the Sep-21 beta. Sorry I was focused on that already-done fillet there, I don't need a pre-filleted version.

Seems to be a bug in the filleter where it is messing up the trimming boundary on that face that then looks weird. The odd thing is that face getting messed up when the actual fillets are done on the opposite side and not connected to it.

One quick work-around for now to patch up this object, is to select the face that is messed up, and use Edit/Separate to break it out from the main model. Then hide everything else, select the 2 edges of the messed up face and hit delete to untrim it and that fixes that face up, then you can show the rest of the model and join that piece back in again.

It looks like somehow the seam edge of the old fillet there was discarded for some reason, making that particular surface have an invalid trim loop.

I may not be able to dig into it in more detail until after the next beta is out.

- Michael

Hi PaQ, I did a bit more investigation - it is a bug in the filleter which is deleting that "seam edge" of the back-side fillet during a post-processing step of filleting where it tries to remove what it thinks are unnecessary edges.

That edge is supposed to be a seam edge so it is not supposed to be removed. However, the surface offsetter did not do a completely good job of offsetting that fillet, there is a very small gap between the ends which is confusing the piece that is supposed to detect whether a given edge is a seam or not.

I'll probably be able to fix that up when I get a chance to look at it in more detail, but also you will can probably get some better quality geometry if you do the shelling first and apply fillets after that, rather than shelling something that has already been filleted. Although there is kind of a Catch-22 there because if you are trying to shell by thickening a surface instead of shelling a solid you may need to have a fully smooth sheet for the surface-thickener to work and not get messed up vertices.

- Michael

Hi PaQ, I was able to fix this up without as much trouble as I had thought, the fix will be in the next v2 beta.

But for the moment extracting the surface out and untrimming it can be done to fix it up now, that will restore the proper trim boundary on that busted surface.

Thanks for posting the bug with the example file!

- Michael

Thanks for you investigation and bug fixing. The extract tips works prefectly.