   character skeletal animation system
  Hi!I'm trying to design a skeletal character animation system because our old one is a bit simplistic and we need an extensible system.Q. Should I use SLerp or SQuad for doing the interpolation between keyframes?My current idea is to make all animations played through a 'mixer'. So when you want to play an animation you add it to the mixer with the parameters.feather in/outblendrepeat (-1 means forever until removed)speed (1.0 is normal, can be negative)sync_cyclesync_delaystart delayAnd an animation has the states IN, STEADY, OUT, STOPPED.The mixer has 2 layers. The first is the blending layer, and all animations added together in this layer are blended together. After this is done, the second overwrite layer, directly applies the transforms subsequently without blending, regardless of the previous one.At each stage (start mixing, stop mixing and start overwrite, post overwrite) the user can register callbacks and also directly modify the data if needed.Is there idea of how to do the IK? Should there be a complex rig defining start and end of IK chains, or just make a whole chain of bones automatically use the start. As an example, the artists can set a chain of bones to copy its root position to that of another bone and then add IK to that.This way you can have the blending of your walk, run and wave, and then a special IK animation on the overwrite layer to correct foot placement on uneven terrain for example.Thanks!   