Yasuyuki Yanagida, Taro Maeda, and Susumu Tachi
Dept. of Mathematical Engineering and Information Physics,
School of Engineering, The University of Tokyo
Proceedings of IEEE Virtual Reality 2000,
New Brunswick, New Jersey, U.S.A., pp. 117-125, March 2000.
Projection-based visual display systems are expected to be effective platforms for VR applications, in which the displayed images are generated by computer graphics using three-dimensional models of virtual worlds. However, these kinds of visual displays, as well as other kinds of fixed-screen-based displays such as various head-tracked displays (HTD) and conventional CRT displays, have not been utilized to achieve precise telexistence in a real environment, which requires appropriate stereoscopic video images corresponding to the operator's head motion. We found that the time-varying, off-axis projection required in these systems has prevented fixed-screen-based displays from being used for telexistence, as ordinary cameras only have fixed and symmetric fields of view about the optical axis. After evaluating the problem, a method to realize a live-video-based telexistence system with a fixed screen is proposed, aiming to provide the operator with a natural three-dimensional sensation of presence. The key component of our method is a feature that keeps the orientation of the cameras fixed regardless of the operator's head motion. Such a feature was implemented by designing a constant-orientation link mechanism.