mesh skinning/skeletal animation


in the last days I tried to play a little bit with skeletal animation, also known as mesh skinning. My intention was to do a little bit “research” for a later project.

I would like to have a cylinder alligned on the -z axis. This cylinder should consist of 3 bones at regular distances so that I can rotate each segment while the vertices get smoothed.
The vertex program I’m using works fine, it transforms each vertex by a matrix and build the weighted sum of all transformed vertices.
For test I’m using only 2 bones. The weight for bone 0 is its distance to the xy plane, the weight for bone 1 is the remainder to 1.0.
My problem is that I’m not sure how to build the bones matrices. Currently both are 2 rotation matrices received from a trackball control.
According to a NVIDIA pdf the matrix is the bones current transformation multiplied with the inverse transformation to the reference posture.I think my rotations are the mentioned current transformations.

Has anyone ideas (or pointers to ideas) where to find further details ??