   Quaternion-based skinning
  So I've successfully implemented skinning on the GPU in my engine and I'm pretty happy with the results but I've read in many places that instead pushing n matrices to the video card, you should really be pushing quaternions and translation vectors.  Better both for speed to the GPU (7 floats per bone as opposed to 16) and also for interpolation between bone positions.  I haven't actually got to the blending/interpolation part yet, so currently, the final position matrices that get sent to the CPU are literally the keyframe animation positions as exported from the 3d content tool.If I were to adopt the quaternion approach, is it just a case of stepping in at the point before sending the final position matrices to the GPU, converting them to quaternions/translation vectors, then doing any clip blending/inter-key interpolation and then sending to the GPU?  If so, does that mean I need to recreate a 4x4 matrix in the shader from the quaternion/translation vector in order to transform the vertex?I might be reading too much into it (as usual), so I'd really appreciate any tips.   
  Don't worry about this one, think I've got all the answers from this.   