@kbar I was able to load OBJs from the Moana dataset in R20 using Python and the ids did align with the Ptex face indices. My method was fairly naïve: loop from face 0 up to the ptex file's faceCount and assume they align :relaxed:
Unfortunately I was using OpenImageIO bindings that I built myself and some of the Ptex files were coming in horribly corrupted. I posted about it to the oiio mailing list but got no responses. I found that solid color tiles might be the cause of the OIIO corruption of the Ptex files and posted an example here: https://drive.google.com/open?id=1z4N3xru0_TPRxVRDoCaQ7ODAUliJRfjM
In the above case the corrupted tiles should be solid white.
Eventually I gave up on solving this through Python + OpenImageIO. I'm trying to pick C++ back up to tackle Ptex but I haven't touched it in 20 years and it's slow going :white_frowning_face: I finally managed to get Visual Studio to build the SDK examples :wink:
At any rate, I don't think there's an issue with the OBJ polygon ids in R20.