Hi Kris – it is possible to store a lot of different kinds of objects in a 3DM file, like NURBS solids, polygon meshes, rendering lights, dimensions and annotation text, etc…

MoI is focused on NURBS modeling only and will only read the NURBS solids out of a 3DM file, not any of the other information (although it will "round trip" such information when you save the file again).

It is likely that the 3DM file saved from Deep Exploration only contained polygon mesh type objects inside of it, which is why nothing was read into MoI.

STL files are also polygon data, so MoI is not able to read those in, since MoI only reads in NURBS data.

STP files do contain NURBS data, but MoI does not currently support this file format, it is something that I do want to add for version 2.0 though.

Probably your best bet is to use an IGES file, which is similar to STP.

But in general if you have a model that is formed as polygons, you cannot read that model directly into MoI.

It is possible to read in the wireframe of a polygon model as lines to use as a snapping aid while constructing a new model inside of MoI – to do that use the OBJ to 3DM converter from here: http://moi3d.com/wiki/Resources#Obj23dmWireframe_converter

- Michael