The avatar is a synthetic human figure that is controlled, wholly or in part, by a real human. Typical applications in current use may make use of a tracking device attached to every segment of the human body. Thus, the human may be required to wear as many as 100 individual tracking devices. One way to reduce the number of tracking devices required is to use the known dimensions and motion constraints of the human body to infer, from a small number of body segments being tracked, the position of all untracked segments. Inverse kinematics allows the computation of the location and orientation of untracked body segments from only a few tracked segments.
Humans carry out functions that are imitated by a synthetic human figure known as an avatar.
Bowen Loftin adjusts a tracking device on the head of a human subject who will direct actions of the avatar. The human body can be modeled as a structure consisting of a series of rigid links connected at the joints. A human body, or any part of it, can be modeled as an articulated figure structure that consists of a series of rigid links connected at joints. The number of degrees of freedom of an articulated figure is the number of joint angles necessary to specify the state of the structure. In developing inverse kinematics, one is interested in finding the joint angles from a knowledge of the end-effector's coordinates.