Hi Michael

Just to say first off that I think MoI is amazing and a pleasure to use. I am yet to discover all its features, but those I have seen so far are just great.
My work is architectural and my main 3d tools are Cycas and Sketchup. I use other 3d modellers (Amapi, Blender, Alibre, etc) to build furniture, bathroom fixtures, etc for my arch models. I have to say that the tools available and the ease of use put MoI way ahead of the other modellers I have used.

So for me it is perfect for modelling say furniture which I can then export as 3ds and import directly into Cycas.

I also need to draw contour maps from time to time for which I normally use Sketchup. But I thought I would try using the loft function in MoI. I usually import an image file into some CAD application and then trace the contours as polylines ( a sort of manual raster to vector conversion), export to Sketchup, position the contours vertically and then use the sandbox tools to produce a landscape.

So to answer your question, the dxf would contain polyline data or at most simple polygon meshes.

I did try saving a 2d contour map file as a pdf which I then imported into MoI. To my surprise it worked perfectly and MoI even managed to get vector data from the pdf.

I will try the route via obj and let you know how it goes.

Steve