Ok, here are some results:
i'm still not sure if this is the only problem / solution, but time will tell.
I made a test file in SU containing
ungrouped objects / grouped ungrouped objects
ungrouped groups / grouped groups
ungrouped components / grouped components
in the first group of 3 all faces were frontfaces
in the second group of 3 some faces were backfaces
in the third group of 3 all faces were backfaces
[image: ZI5c_severalfacesreversedSU.jpg]
The result in Max was, that only the objects containing some reversed faces got these faces triangulated. If all faces were reversed, no face got triangulated.
[image: V2qG_reversedfacesgettriangulated.jpg]
Then i tried some objects, checking what i saw in the video- and i'm quite satisfied with that, i don't see the reason for me to quad everything as long i don't work together with someone who needs quaded objects or whose program triangulates everything if it's not getting quad geometry. Btw, "removeinnerfaces.rb" works great.
[image: a1xV_severalobjects.jpg]
[image: 0dhU_severalobjectsinmax.jpg]
One thing to mention is that some backfaces corrupt adjacent faces, as you can see in the Max file.
Some get triangulated themself, some triangulate their neighbours and show themself as a "strange material"
We'll see if there are still problems coming up not getting solved by checking for backfaces..
Anyway, it's a litte piece in the puzzle- maybe someone can take advantage from that in the future..