[Algorithms] Quaternions in IK

[Auday <au...@so...>]

Hi all ,

Does any one know an efficient way of constraining quaternions in IK 
without factorizing them into 3 axis quaternions ?
Finding the required rotation quaternion in IK is pretty easy , but how can 
we make sure that it doesn't violate or 3 constrains of the 3DOFs of the 
joint ? what I'm doing now is factorizing the IK result quaternion of the 
joint into xrotation quaternion yrotation quaternion and zrotation 
quaternion , constrain them by their maximums and recombine them again , 
which is obviously a very expensive process.

any ideas ? or maybe references ?

Thanks

Auday