Custom 3dm Import/export


Hi Guys,
I have a Question, does anybody ever make a custom 3dm Import export for another cad Software to be able to import Rhino Files natively?
Is this possible at all?

(Dale Fugier) #2

HI @jj1,

Yes, this is possible using our openNURBS toolkit.

– Dale


Thanks Dale- (sorry for the multiple topics, but I wasn sure where this question would fit best)

So how is it done ?
Do you have to be a scripting professional to be able to do this?

I have two Software packages that I would love to have a direct 3dm Import…
That is Alias and Blender-
For both there doesnt seem to be an 3dm imort/export available.

Which coding language would be used for building such an importer? C#, python?
We do have a developer in our team, who is expert in C# ( python as well) , but he is to buisy -he could eventually support me a bit, as I am currently starting to get into python.

(Dale Fugier) #4

For Rhino to Alias: you can export STEP or IGES files, from Rhino, and open them in Alias.

There is also this:

For Rhino to Blender: you can export LWO and OBJ files, from Rhino, and open them in Blender.

Does this help?

– Dale


HI Dale,
Of course I can export data to Alias and Blender-
but i would love to keep my Rhino File structure, Layers, (basic) materials, naming …
I usually organise my Rhino files quite well, meaning I put a lot of effort into it. Its a waste if that is lost when switching between Applications.

Also- there seems to be not a single export fotmat (out there) which is able to handle Nurbs AND Mesh Data…

Using Step or Iges, I loose my Meshes.
Using Obj or other Poly format, I loose all my Nurbs (or have ti convert them to mesh)
Plus the loss of File structure…

I think 3dm is the only “complex” format that is both, free to use, and able to handle all kinds of geomtry!
So in my opinion It would be perfect.
Plus, I am curious if I would be able to code it my self (with some help of you guys and or my teammate)

(Dale Fugier) #6

Rhino’s 3dm file format does this.

Keep in mind that other application do not support all of the types of geometry that a Rhino 3dm file has. Thus, it becomes difficult to round trip a 3dm files with other applications.

But if you want to looking this, here is where you can find openNURBS.

– Dale


I was hoping for a little hint how or were to start.
Also outlining the effort to do this.
Again, the question was If anybody already did this- and if so, what were the experiences.


ideally there is a “tutorial” on how to intergrate 3dm format into Any 3d Software :slight_smile:

(Dale Fugier) #9

Hi @jj1,

This isn’t really possible, as every application (and their SDK if they have one) is different.

Writing file I/O plug-in can be very difficult. Not only do you need to know the importing/export format and API (3dm in this case), you also need to know all about the hosting application and what it is capable of.

– Dale

(Nathan 'jesterKing' Letwory) #10

For Blender there was a GSoC project in 2014 where adding openNURBS support was attempted - see the branch


Thanks Nathan, I will try to investigate the Blender implementation :slight_smile:

@ Dale which Scripting klanguage is needed to writr such an importer?

I found a link-
that might be helpful, but its mentioning c++

(Dale Fugier) #12

This is a question you need to ask of the application you are importing into; Alias or Blender. This is the environment you’ll be doing your development, not Rhino.

– Dale