Motion Capture for Computer 3D Character Animation

Abstract

The process of recording movement and translating that movement on to a digital model is called motion capture or motion tracking. The technique was originally used for military tracking purposes and in sports as a tool for biomechanical research which focused on the mechanical functioning of the body, like how the heart and muscles work and move. In filmmaking it refers to recording actions of human actors, and using that information to animate digital character models in 2D or 3D computer animation. The information captured can be as general as the simple position of the body in space or as complex as the deformations of the face and muscle masses. Motion capture for computer character animation involves the mapping of human motion onto the motion of a computer character. The mapping can be direct, such as human arm motion controlling a character’s arm motion, or indirect, such as human hand and finger patterns controlling a character’s skin color or emotional state. When it includes face and fingers or captures subtle expressions, it is often referred to as performance capture.
Motion capture has become an essential tool in the entertainment business, giving computer animators the ability to make non-human characters more life-like. In the entertainment application this technology can reduce the costs of keyframe-based animation. This work presents a detailed study on the techniques used in motion capture for 3D character animation.