In animating motion of a human-like articulated figure, inverse kinematics is usually used. Previous approaches to the inverse kinematic problem require vast computing power since solving for the inverse or pseudo inverse of Jacobian matrix involves non-trivial non-linear optimization. In general, Jacobian matrix is singular and the size of Jacobian matrix is increased by increasing the number of joint. However, pseudo-inverse matrix of the 1-joint problem Jacobian matrix in the 2-D space is easily obtainable. This leads us to investigate a mechanism that decomposes the 3-D problem into multiple 2-D problems. In fact, the n-joint problem in 3-D is transformable to the 2-D and 1-joint problem by using the coordinate system transformation and the virtual segment. In this paper we apply this technique to the animation of human figure using the geometric and physical motion control methods.
