Rhino3dm.net read custom userdata


I would like to know if there is a way to read custom UserData.

The userdata was writen from a rhino plugin. And I do know the GUID and the definition of the userdata.

However I could not find a way to read this userdata in rhino3dm.net, even though I tried to get the data with the same type. It always returns null.

I noticed that I can read it in rhino plugin as this userdata is somehow “registered” when rhino is loaded. But with rhino3dm.net this step seems to be missing…

I would be very grateful if there’s a solution.


Hi @jessen.ch,

You can certainly read user text, both object and document. I also believe the ArchivableDictionary class is in Rhino3dm. However, I do not beleive it is possible to read customer, UserData from objects. @stevebaer, correct me if I am mistaken.

You can read custom user data, using openNURBS, if you wrote it from a C++ plug-in.

– Dale

The stand alone Rhino3dm currently does not support reading custom user data written by a plug-in. We can add this functionality, but it will take a while before we can get to it.

Thanks a lot for the reply! @dale @stevebaer

Does it mean it’s also not possible to write custom userdata from Rhino3dm?

The data is indeed written from C++, meaning there’s a chance to read it. But isn’t Rhino3dm the .net version of openNurbs?

No, I don’t believe this is possible at this time.

Yes, Rhino3dm is based on openNURBS.

If the data was written from C++, why do you read it from C++?

– Dale

Thanks for the reply @dale Basically we are trying to read a 3dm file exported from Cadwork(another cad application), which contains userdata defined by them. We’re figuring out a solution to read those userdata externally.

Does it apply to this situation?