Hi Brian, ok now I understand that you are comparing importing .3dm files versus importing .obj files into Carrara.

When you import a .3dm file directly into Carrara, you are relying on Carrara's meshing code to convert NURBS surfaces into polygonal facets. It does not look like it did a very good job of that conversion in this case.

When you import an .obj file into Carrara, you are instead relying on MoI's meshing code to convert surfaces into polygons. MoI's conversion mechanism tends to work better, that's why you get better results when doing it that way.

- Michael