Motion Pattern Preserving IK Operating in the Motion Principal Coefficients Space

We introduce a constraint-based motion editing technique enforcing the intrinsic motion flow of a given motion pattern (e.g., golf swing). Its major characteristic is to operate in the motion Principal Coefficients (PCs) space instead of the pose PCs space. By construction, it is sufficient to constrain a single frame with Inverse Kinematics (e.g., the hitting position of the golf club head) to obtain a motion solution preserving the motion pattern style. Such an approach also reduces the size of the Jacobian matrix as the motion PCs space dimension is small for a coordinated movement (e.g. up to 9 for the golf swing illustrating this paper). We compare this approach against a per-frame prioritized IK method regarding performance, expressivity and simplicity.