1 Introduction

This paper lays out research into the use of motion tracking technology for real-time, embodied telepresence ad collaboration. The central question underlying this essay is, "In what ways can telepresence and collaboration be enhanced by motion tracking technology in performance and installations?"

Preliminary findings suggest that motion tracking technology makes it possible for multiple users to manipulate not only data objects like images, video, sound, and light but also hardware and equipment, such as computers, robotic lights, and projectors, with their bodies in a 3D space across a network. Implications for use of such enhanced telepresence may be of interest to those working on digital media projects where hardware, software, and peripherals must be controlled in real-time by teams working together at-a-distance or where physical computing research is undertaken.

It begins with a brief explanation of the evolution of the motion tracking technology called the GAMS system within the context of motion sensor technologies, providing, along the way, examples of projects undertaken at each stage of its innovation; the paper, then, moves to a detailed discussion of GAMS' application to two networked performances where embodied telepresence was used to enhance collaboration.

2 Motion Tracking Technology and the Evolution of the GAMS System

Motion tracking technology has been used for surveillance and training, virtual reality experiences, smart rooms, human computer interfaces, and health and therapy programs (O'Sullivan and Igoe xxvii-xxix). In terms of its use for projects involving real-time interaction in the production of graphical and media art, it was pioneered by , whose Very Nervous System (VNS) was developed between 1986 and 1990. That system, described as a "third generation of interactive sound installations," utilized "video cameras, image processors, computers, synthesizers, and a sound system to create a space in which the movements of one's body create sound and/or music" (Rokeby). In effect, the system made collaboration possible between installation and performer, resulting in a "state of mutual influence," a condition Rokeby referred to as "interaction" (Wilson 731). Thus, at this stage of development motion tracking, or motion sensor technology, as it is sometimes referred to, consisted of non-networked experiences focusing on one user interacting with computing and media devices.

In the late 1980s, influenced, in part, by Rokeby, engineer-artist Will Bauer, of Acoustic Positioning Research, Inc. (later, called APR), created the first iteration of his Gesture and Media System, calling it at the time the Grid Activated Sonar Production, or GASP.

Figure 1. The ultrasonic system