When I use intersect command to get a nice 3d curve I'm getting incorrect results (Windows 10, locale set to pl_PL).
The resulting curve usually has some overlapping segment which totally messes things up. It seems MoI has issues with intersect when the result should be a closed curve.

I have a short video recorded (13 megs), but the forums do not allow me to attach it (I'm getting 500 Internal server error).

Hi Przemas, I can confirm that's a bug in the surface/surface intersector in the geometry library. I'll investigate it to see if I can figure out what's going wrong. Thanks for posting the .3dm file so I could reproduce it over here.

- Michael

Hi Przemas,

Is it possible to send link for downloading the video?

Thanks
Mik

sure, but the link will expire shortly:
https://we.tl/t-5hdUMOz9E7

It hit me when I've been running a workshop on using digital tools to create jewelry - I've suggested MoI trial to the participants and we've been working on a simple signet ring with sweeps. In the end I had to tweak my plan a little and had to use single rail as at first I didn't noticed what's wrong.