5. Artistic Considerations in the Use of Motion Tracking with Live Performers: A Practical Guide

1) Motion tracking describe systems in which video cameras are attached to computers. With the cameras focused on humans in motion, data can be collected and processed for any number of purposes.

2) Motion captute
It implies the recording of movement data for later processing. Systems such as Vicon are used routinely in the motion picture industry to create animated characters with realistic animal or human movements.
By wearing reflective balls attached to certain positions on the body, a collection of points moving in three dimensions is calculated by computer.

3) Motion sensing
EyeCon is a system designed to give a sense of the motion, rather than exact data on position and motion. While Eyecon does indeed have a feature to allow it to monitor the positions of individual performers on stage.

4) Merce Cunningham, 'Biped'
a dance piece in which dancers appear both in the live sense, and in the form of projected animations.
It is not a realtime system. The motion-captured data was processed in advance, and then projected simultaneously with dance.