3D model program?

[Karlos]

Any .obj format as used by a game like payback is almost certainly going to be a custom format that is optimised for the game engine. Don't expect compatibility with any known packages unless the documentation for the game states otherwise.

More than likely, the game developers have their own custom tools for either editing models or converting from a commonly supported format to their own format.

[Karlos]

Given my first post seemed lost, question:

How do we know the files in question are wavefront object files?

Just because the extension is .obj means nothing for an application like a game which typically has custom editors and converters developed for it.

Heck, .obj is also the compiler output of my Watcom IDE. It is also the extension I used for a object format in my old game engine. It is also the extension used for objects created by the AMOS model editor that came with the AB3D-II editor set. The .obj choice of extension is a logical one for anything you could call an object :-)

Unless you know from documentation or by looking at the file signature in a hex editor, how can you be sure it is the specific .obj format supported by 3D package X?

It's like assuming anything ending in .raw is a raw sound sample.