Hi Paul, thanks for sending me the file in e-mail.

So your problem is one of the last things I mentioned above - you don't have any NURBS surface data in that 3DM file, you only have polygon mesh objects.

Rhino supports several different kinds of data in 3DM files, things like NURBS, polygon meshes, dimensions & text, spotlights, etc… but MoI is focused only on NURBS modeling and will only read and write NURBS objects from a 3DM file and will not read in polygon mesh data that might be in the file.

But since you have the object as polygon mesh data already, it is actually ready to be imported directly into Modo without trying to bring it into MoI to convert it.


To bring the data into MoI you need to have the original CAD data, which will usually be in either an IGES or STEP file. That will contain the actual original NURBS spline surface data in it instead of a bunch of faceted polygons, and that spline data is what MoI is set up to be able to import.

MoI can _export_ to various mesh formats, at which time it will break the smooth spline surfaces down into polygonal facets to store as a polygon mesh, which you can then load into a polygon modeling program.

Typically you will want to do the mesh conversion in MoI instead of in the original CAD program itself, because MoI has a much better process for doing that part.


So you'll probably want to go back to whoever is sending you these files, and ask them to send you the original CAD data (preferably in both IGES and STEP formats) and not to send you only already triangulated polygon mesh data.

- Michael