Problems with surfaces, when importing from Autocad 3D

I did some 3D models in Autocad and now I am trying to import them to Rhino, but a lot of the surfaces disappear, especially curved circular surfaces. Everything is a 3D solid.
These 2 messages appear:

  1. “An invalid polysurface was read. Would you like to salvage as much as possible of invalid polysurfaces?”
  2. “Invalid surfaces will be removed from polysurfaces and returned in separate polysurfaces with object name Bad Faces”

For example, it also happens to this this, the top surfaces not just disappear, but also other geometry is changed… :frowning:

disk rhino problem.3dm (102.8 KB) Disk.dwg (243.5 KB)

Rhino 6

Your .dwg seems to open correctly here in V6 and V7… In both cases the object is valid, but it is open on the underside…


I don’t understand why it forms those new surfaces…
Is autocad a bad program do model objects to export?

What new surfaces? The imported Rhino model looks like the image of your Autocad object.

This object can also be extremely easily modeled directly in Rhino.

There’s a trimming error on the underneath part of the sphere in your part. Rhino keeps the wrong part of the surface.

This part is really easy to model in rhino, the problem is that this is only one part out of 400 complex ones that i’m not showing for simplicity.

Both images are not the same. Autocad one has a hole in the middle, while Rhino one has closed that middle hole.

@lowell that link is invalid, what is it?

@lois - The link is to a bug report about Rhino not reading your part right.
I adjusted some permissions and I hope it will work for you now.

Sorry, still can’t see it. Tried registering so I could login and read it, but it also fails, give me the message:
“License limit exceeded. The request cannot be completed.”
Thanks for trying! Do you think that link had the answer to the problem?

Hi -

You should be able to see it now.

The link is to a report in our public bug tracking system.

This bug is now a task on Lowell’s to-do list and, from what he knows now, he expects to be able to fix this in a Rhino 7.x release.

OK, sorry I missed that - it was late… :flushed:

Probably not. Depends on the objects. I would simply venture to say that Rhino can probably model anything that AutoCAD can and then some.

@Helvetosaur Yes, I know that Rhino is better for modeling, it’s just that I have 8 years of Autocad experience, and just this year I’ve been slowly transitioning to Rhino. I know it’s a matter of time, but I still take too much time to model in Rhino. Hope this changes in the future.

Thanks for the help.

@wim I can see it now, Thanks for addressing this issue! I’ll skip what I wanted to do for now, since I can do it in Autocad, but hopefully in the future I’ll be able to successfully import autocad 3D to Rhino without these issues.