Re: Looping rotation

It is not a maths what you need! just a small trick.
t and end in
In max you set frames range you want to actually render.
then you try using 'home' & 'end' key which makes your scroller jump to start and end.
then you see exact position/rotation & orientation of your object at exact start frame and end frame.

here you can make it fine tuned to make seamless loop.

once satisfied......just render

thats all!

I guess I understood your prob.