Hi Nick, so there are some various difficulties with several of those formats.

.wrl is a polygon based format, things like a sphere in a .wrl file are made up of a lot of little triangular facets and not an actual smooth sphere surface. That's a pretty different type of data structure than the NURBS surfaces that MoI works with.

.dwg is a proprietary format from Autodesk which is not very easy to deal with without using some special kinds of libraries. There is a companion format called DXF which is actually documented (for 2D stuff anyway, NURBS solids are not documented).

.bip I don't think is publicly documented. I think it is a text file format so it could be possible to figure it out but having an official public document that describes the file structure helps a lot when trying to make an exporter for that format.

.bip is pretty specific to just one particular rendering program - just in general with MoI it's more feasible for me to work on file formats that tend to be used by a variety of different programs for file transfer instead of ones that are specific to just one program. OBJ format already contains the exact same kind of data that would go into a .bip file...


- Michael