Introduction

Kinematics in computer animation is usually divided into two basic parts - forward kinematics and inverse kinematics. Forward kinematics is based on the manipulation with the structure, that is done by changes of the joint angles inside the controlled structure (Figure 1a). Inverse kinematics is based on the direct manipulation with the end of the structure and the joint angles are derived from changes of the end of the structure (Figure 1b).

Figure 1: Process of manipulation of the structure through a) forward b) inverse kinematics.

Since inverse kinematics makes possible to manipulate the articulated structure by the end effector, it could be used in animation techniques for easy motion control.

The problems relating to the inverse kinematics are known for a long time and are in more detail described in the literature, e.g. [WW92], [Wel93], [Chi96].