I have tried to stay away from .3ds because it has several limitations - .3ds files are limited to triangles only (instead of allowing many-sided polygons), and they have a size limit of 65535 points/polygons for a single mesh. And in addition they don't have the ability to contain a type of smoothing information called "vertex normals". The .obj format doesn't have these limitations.

Most software that can read polygon information can handle .obj files, but I guess that there are unfortunately a few that don't - I guess Sketchup is one of these. Are there others?

I guess that I can add .3ds format if it is really necessary. It is actually a lot less work to add .3ds than DXF/DWG.

- Michael