Quote:
Originally Posted by Norb
lol, I wouldn't know what to do with that matrix once I made it :P
I'm still wrapping my head around 3D math again as I haven't had to use if for quite some time.

A 3x3 matrix represents rotation + scaling, and it's just three vectors determining the direction (and magnitude for scaling) of the three axis.
To get one from a poly face get the normal, get a vector from an edge (adding the vectors of the first and second point of that poly face) and that gives you a reliable upvector, except for very messed up shapes.
Once you have those you can run a cross product of your normal by your upvector, and that will give you a working binormal (the second of your axis). Another cross product between that and the normal will give you a third orthogornal axis, the third one. And you're good to go and can populate that matrix.
For the second vector it's also an option to project (and normalize, unit in maya) that upvector on the orthogonal plane of the normal, but it's slightly more involved than just running a cross product.
If you're not familiar with cross products, I suggest you look them up as part of an elementary study in linear algebra, there's only that far you can go without knowing at least the basics