in 3dsmax SDK ive got a structure named MAXPOS (float x,y,z,w). 3dsmax usues this struct also for storing rotation vector (?). my problem is that i dont know how to code it. For example:

Ive got a vector (0.5, 0.5, 0) and a the rotation vector (0, 0, 0.707, 0.707). in the editor i sees this point rotated 90 deg with z axis. What is the formula to calculate it?
0.707 is exacly sin(PI/3) but i want PI/2!

nothing about my problem.
iam absolutely green in quaternations, and i dont know how to process object rotating with only four values. they differ of what i see in my 3dstudio. the seems to be some trig functions, but their values arent equival to these i have.

nothing about my problem.
iam absolutely green in quaternations, and i dont know how to process object rotating with only four values. they differ of what i see in my 3dstudio. the seems to be some trig functions, but their values arent equival to these i have.