What are quaternions used for? Math to determine vectors? Also, I'm a little rusty on matrices. Anybody got a simple explanation on what they are used for, and how they work (ie how they multiply out)? Finally, are either quaternions or matrices used in the tform commands? I guess I am a dunderhead (dunce, dolt, blockhead, thick-skull, etc) on these, but like my sig says, when in doubt, find out.