I have the 3d global positions of a set of joints as they move over time and the ik skeleton structure which relates them. I am currently writing some code to convert this information in .bvh file. I understand the .bvh structure, but what I need to do for each frame is convert the global coordinates into a series of local matrices which represent the transformation to "move" from parent to child for each node.
What I don't know how to do is calculate the local matrix for the transformation for instance to go from
rootNode = (Rx,Ry,Rz) and lets presume that initial orientation is in line with the global axes
child1 = (Cx,Cy,Cz)
and so on.
Any help much appreciated.