Made face flipping heuristics optional, it messes up scenes that are ok.
For scenes that after exporting have objects with flipped normals, original assets can be fixed in Max in a following way:
1. find out problematic objects in Max
1. select all objects
2. set View -> xView to show "Face Orientation"
3. select all object that are fully/mostly green
4. in Utilities apply Reset XForm to selected objects (this will show messed normals also in Max, otherwise they are hidden)
2. fix problematic objects
1. apply Normals => flipNormals modifier to selected object
Hope so. At least now hacked face normals correspond to face normals computed from scratch in Geometry.
(If only max didn't have zillion ways how to achieve the same visual results :/. I tracked this flipped normals/faces business down to XForm modifier - it doesn't get collapsed properly when making TriMesh / Editable_mesh snapshots. At least Editable_mesh snapshot differs in way that is exploitable for workaround hack.)
alteredq