Hi stefan, also even if MoI did write out render mesh data attached to NURBS objects in 3DM files, I think you will be getting some reduced functionality if you tried to read that data rather than loading in an OBJ file.

For example, I don't think that 3DM render meshes can have n-gons in them.

Also MoI is able to apply different materials to individual faces out of a solid, which does not really map to Rhino - Rhino is limited to have only one layer assigned to a whole solid and can't assign different layers to individual faces in the solid like MoI is able to do.

Also 3DM meshes are not able to have a welded vertex structure where 2 faces share the same 3D vertex point but have separate vertex normals and uv coordinates for the face, rather than sharing everything.


If you try to read only 3DM mesh data instead of OBJ mesh data you're going to end up with all the limits that are imposed by Rhino's older style mesh structure. You won't be getting the full fidelity of what MoI's mesh export is able to produce.


MoI is able to handle mesh data in a more flexible way and can produce these other kinds of mesh data like n-gons, welded points with different normals, different materials per face of a single solid which work in an OBJ file but won't fit in a 3DM mesh file.

With those limits, 3DM is just not really a great file format for storing mesh data in general, it was never really the primary focus of the format.

- Michael