Hello All!
I’m at my wits end here! I’m working on lag-reduction in my First Person Shooter, and now it’s just a case of adding some extrapolation.
I can extrapolate position; getting the last two positions and the velocity from them, then adding the velocity to the existing position (* delta time).
However, i cannot do the same for rotation.
By default, the angles are Euler, but i can (and do) convert them to quaternions as they can suffer gimball lock.
How would i extrapolate a new orientation from 2 previous orientations?
I have time between packets, 2 packets and current orientation.
a LINE between vectors? L = V1 + alpha*(V2 -V1) ?
alpha = 0, you are at V1, alpha = 1, you are at V2 so, alpha >1 is a further on the line (‘vorbei’) V2 
give it a try
with V1 and V2 quaternions