strange MAX exporting problem...

Hey all,

Somewhat off topic, but this forum is probably better than forking out the money to Discreet only to find that their SDK support can’t help me… (didn’t help at a past company for a number of issues.)

OK. Strange problem exporting UVs from 3DSMAX with a custom exporter:
I export the UVs just like I did with previous exporters and previous versions of 3DSMAX (versions 2.0, 2.5, 3.0 and 3.1). But with my exporter ported to version 4.0, I find that I need to swap the UV face indexes for face 0 and face (numFaces / 2)!

That’s right, the UV face indexes for the first and the exact center faces are exporting swapped.

Yet, I am 100% positive that the method which I get the UVs and their face indexes is correct.

The same problem exists for all mapping channels too.

Has anyone else noticed this? I’m very sure that this is not a bug in my exporter or my run time loader code- I just spent time verifying that the data is incorrect INSIDE Max 4.0. They must have a hack fix inside the geometry rendering pipeline that corrects for this within their logic, because these faces render correct inside the MAX UI renderer and their other renderers.

So, anyone else know anything about this? Anyone else run into this issue?


Did you swapped the Y and Z axis? Usually this is the reason objects and UVs are wrong when loading 3DSMAX objects…

I’ve got my engine running in the same coordinate space as 3DSMAX, so I don’t need to. In addition, I have logic that allows me to flip the Us or the Vs to see if the geometry needs to have one or both of the coordinates flipped (1.0f - coordinate); and that’s not the problem.

Really quite strange- just those two faces have problems, and the problem can be fixed by assigning them each other’s index values.


I got the exact same problem with my exporter, it works perfectly in max 3.1 but in 4.0 the texcoords are messed up. no idea why, I “solved” it by using 3.1 to export the scenes, but that is ofcourse not a good solution.

There is a VERY good discussionboard at, try it, and if you get an answer please tell me.