Anybody have a CAD file that C4D can't import?


We’ve converted literally hundreds of STEP files since R20 and not run into an issue where we couldn’t open a file. We got a step file from a client that R21 has been working on for an hour and still going, I think. Not sure when to give up as I’ve never seen this before? Watching the task manager and the cpu and memory usage and things seem to be fluctuating but can’t tell. Anyone been in this situation since R20? It’s only a 34mb file, but I’m not sure how much of a difference that makes with a parametric file.


No problems that I can recall for myself. It’s been one of the most useful recent features for me.

Are you importing using ‘source mesh’ tesselation - or scale based / custom?
Just wondering if the scale might be causing some massive amount of tesselation or something?

The other thing that comes to mind: What are your settings under Modifications > Combine?


Agreed. C4D’s CAD converter has been stronger than another piece of software we paid thousands more for in the past

Neither of those options are checked. Never used either ever.

Attached are my current settings

I wonder if the version of the step file makes a difference? We told them STEP 214 but I’m not sure what version of step this is, if it makes a difference.


We’re trying other formats on the assembly, on the phone with the engineer, apparently there is a detailed bone in the scene as well which is an stl file. Quite certain that’s the culprit at this point. More soon.


Yes - nothing unusual in your import settings…


Hi, I once had a STEP-file which took around 24 hours to open. With scale based tesselation.
Opened it over night and used R21 to work (or R19) while R20 was converting.
But finally it was there and everything ok.


Wow! Maybe we’ll give that a try and see what happens.


So we separated out components and the culprit is some threaded rods. We’re currently at about the 22 hour mark on the conversion process and it’s gotten to the Heal phase. Healing tends to fix issues we normally see with threaded parts. More soon.


fingers crossed!


Absolutely - I hope you get a workable file. Threaded fixings and holes can be a real pain in any CAD to poly conversion.


Almost 48 hours later and the threaded rods are still going. Dunno. Been on Healing most of the time. Things with threads sometimes have issues that healing fixes. Might not have been the best move but never seen this before. I think the plan now is to abort and get a single rod and recreate that part of the assembly. Everything else converted fine. It’s a pretty complex assembly.

Thanks guys!


48 hours :open_mouth: Wow that is… odd. Surely there must be some corruption or something?
Keep it running or abort? You never know if it’s just about to finish…

Might be interesting to let Maxon have a look - if your NDA allows.


Its running in R20 while I work in R21, no biggie. That’s just it-you never know. It could run another week at this point, who knows. We’re in deep ocean territory now.

These are just 8 structural rods which are identical, so I’m not too concerned, the concerning parts all came in fine. Would be good to know whey these are choking so hard, but otherwise I’m fine aborting and going simpler to finish the project.

I can send it to Maxon for sure, they are simply threaded rods. Take a cylinder of a certain length and thread it. That’s it :).


as other option, we use rhino3d for any file conversions, this usually opens also step files fast and without problems for us. they also have a 30 day demo in case for testing


Thanks Stephen. Wow, I haven’t touched Rhino since the mid 90’s. I’ll give that a quick go out of curiosity. We haven’t been able to even look at the file with a STEP viewer. We were able to get a single rod in the lowest setting but it had something like 20 duplicates of things on top of the mesh which was odd.


well for architecture at least rhino is one of the most widely used programs still, and very active (in special with grasshopper), it opens almost everything.