Character animation

Abstract

Motion control is one of the important components of animation. The process of creating motion of an animated character usually involves articulated model as shown in Figure 5.1. Character animation can be described as the movement of multiple articulated joints hierarchically. All the articulated joints are connected by segments in a hierarchical form. Then, it is combined with a 3D geometric model such as polygonal mesh. The trajectories or orientations of the joints are specified in the skeleton. The change of a root joint propagates to other sub-joints. For example, a rotation of hip joint made the entire leg to rotate (Jing 2005). There are four main techniques for creating 3D character animation: keyframing, kinematics, dynamics and motion capture. In keyframing animation, the key values for the animated DOFs are specified by animator while the computer interpolates between these values. Motion capture is the process that is used to record the movements of the objects and to map the movements to a virtual character. These three techniques will be discussed in this chapter.