Hi Matteo - that converter is only a simple conversion tool that translates curves in a 3DM file into a curves in a DXF file.

It does not process solids or surfaces or do hidden line removal to generate a full 2D drawing from a 3D object, so that particular tool just ignores any solids or surfaces that you have in the 3DM file.

I'm not quite sure from your description what it was exactly that you were trying to convert - was it a file that had all curves in it or were you trying to convert solids?

- Michael