Hi Mangrove, are you able to do an IGES format export from AutoCAD? I don't know if AutoCAD still includes an igesout command or if that is something you need a plugin for these days.

IGES format can contain curves and lines (as well as surface data), and IGES also contains a flag for unit system. MoI will read this flag, so if you open an IGES file, your units in MoI (which are settable under Options) should end up the same.

You could also use Rhino as a converter, since Rhino can load a DWG or DXF file directly and then save to a .3dm file that MoI uses.

I want to add direct DWG or DXF support into MoI, but it is a fair amount of work so it's not going to be available for the initial 1.0 version.

- Michael