Hey, basically I come across a specific error in asset manager while trying to convert a model.

Code:
fabs( Vec3Dot( vert->normal, vert->tangent ) ) < EQUAL_EPSILON
Tried to search the web but without success, I did in fact managed to find some references (not related to cod2 but similar problem) but I am not that much into modelling and I can't really understand what the problem is.

Would really appreciate any Intel on this kind of problem in cod2.