When importing 3d stuidos .ASE files into my OpenGL program, I noted something strange, it used following information to record state of Pivot:

- translation vector
- scale factors for x, y, z axis
- rotation angle and rotation axis (which is represented with x,y,z coords)

Transformations are ment to be used in following order: M = T*R*S (I’ve tested this)

Now, strange thing is that all rotations are represented with only 4 variables: angle[1] and axis[3]. Is it posible that composition of N rotations can be substituted with single rotation around arbitrary axis??

If this is true, can I find more about it and similiar facts in form of mathematical theorem/theory?

Thanks for every info!