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Proceedings Paper

Improved temporal response in virtual environments through system hardware and software reorganization
Author(s): Richard H. Jacoby; Bernard Dov Adelstein; Stephen R. Ellis
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Paper Abstract

Excessive end-to-end latency and insufficient update rate continue to be major limitations of virtual environment (VE) system performance. Beginning from a typical baseline VE in which a spatial tracker is polled to deliver data via an RS-232 interface at each update of a single application program, we examined a series of hardware and software reconfigurations with the aim of reducing end-to-end latency and increasing update rate. These reconfigurations included: (1) multiple asynchronous UNIX processes communicating via shared memory; (2) continuous streaming rather than polled tracker operation; (3) multiple rather than single tracker instruments; and (4) higher bandwidth IEEE-488 parallel communication between tracker and computer. Starting from an average latency of 65 msec and an update rate of 20 Hz for a standard 1000 polygon test VE, our most successful implementation to date runs at 60 Hz (the maximum achievable with our graphics display hardware) with approximately 30 msec average latency. Because our equipment and architecture is based on widely available hardware (i.e., SGI computer, Polhemus Fastrak) and software (i.e., Sense8 WorldToolKit), our techniques and results are broadly applicable and easily transferable to other VE systems.

Paper Details

Date Published: 10 April 1996
PDF: 14 pages
Proc. SPIE 2653, Stereoscopic Displays and Virtual Reality Systems III, (10 April 1996); doi: 10.1117/12.237447
Show Author Affiliations
Richard H. Jacoby, Sterling Software, Inc./NASA Ames Research Ctr. (United States)
Bernard Dov Adelstein, Univ. of California/Berkeley and NASA Ames Research Ctr. (United States)
Stephen R. Ellis, NASA Ames Research Ctr. (United States)

Published in SPIE Proceedings Vol. 2653:
Stereoscopic Displays and Virtual Reality Systems III
Mark T. Bolas; Mark T. Bolas; Scott S. Fisher; Scott S. Fisher; John O. Merritt, Editor(s)

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