During Rhino 3DM import:
● Points are imported as a group of 3D loci.
● NURBS curves are imported as a group of NURBS curves.
● NURBS surfaces are imported as a group of NURBS surfaces.
● Closed solids are imported as a group of imported solids
● Open solids are imported as a group of NURBS surfaces.
● If there is only one element in the Rhino 3DM file, it is imported as a single element rather than grouped.
Imported solids cannot be ungrouped or edited through the Edit Group command; they can be used in solid operations.
To import a Rhino 3DM file:
Select File > Import > Import Rhino 3DM Format (3D only).
The Import Rhino 3DM File dialog box opens.
Select the file to import, and click Open.