I just wanted to confirm here that I’m not crazy (or am I?).
I did a forum search and found that a few other individuals have had various issues with some of the mesh importers/exporters.

When exporting or importing a simple flat plane, Max’s vertex order is always reversed for the .obj and .stl formats.
These are the only formats I’ve tested so far, so I cannot comment on the others yet.

A vertex order that is counter-clockwise has a positive Z or “upward” or “outside” normal (the right-hand rule).
In the case of a plane along the XY, it would be classified as positive Z for a counter-clockwise vertex order.  eg. the faces would be shaded on the top side.

Max does not adhere to this and uses clockwise as positive Z order when importing and exporting .obj and .stl.

This really isn’t a serious issue with the project I am working on, other than the fact that importing/exporting always requires a change to the vertex-order (in the other software eg. exporting as clockwise for Z+) or a face select all and flip in Max.

Has anyone/everyone else noticed the same issue and why is Max doing this backwards?

Thanks,
DG

EGI Integrated Partner - Software and Game Developer