Dissapearing lines in export to dwg

I have a problem of dissapearing lines when I’m exporting my work to a .dwg. I am being sent .igs files, do what I need and then after exporting to cadfile, there are no some lines. Sometimes it is so only with one type/layer, sometimes dissapear 3/4 of one type. Any suggestions?

Can you post a Rhino file that shows this behavior, along with your .dwg export settings? That would help us try and find the problem.

L06_S07_CAI01.3dm (16.5 MB)
I shouldn’t, but here it is. In this case dissapear all purple fins.

If you run SelBadObjects on your file you will see a lot of objects select (105!). I think those will be all of the ones that are missing in the export. Rhino does not export objects that it considers “bad”.

Also, those are not curves (lines) you are exporting, but surfaces. The way to fix those is to untrim each one keeping the trim objects, then re-trim… However, with 105 objects, that will take some time.

Were these objects already bad when you imported them, or did you do something that caused them to go bad?

I just checked. After importing an .igs file and running SelBadObjects only 15 open surfaces are highlighted as bad, so I have done something that caused remaining 90 to go bad. What can sause it? I was only coppying and rotating the model.

Hello - please zip the igs file and send to tech@mcneel.com to my attention, I’ll have a look.

@adamredzik522 - thanks, I got your file - one thing I see is that the objects are very far from the world origin and if I move them to the origin more faces go bad, including the ones that are disappearing in your workflow.