Effects of Frame Rate and Delay

We have performed a series of studies of the effects of frame rate and delay. In general we find that open-loop tasks such as shooting are not very sensitive to frame rate, while closed-loop tasks such as placement and tracking are very sensitive. It is not particularly important to maintain constant frame rates as long as mean frame rates are already reasonably high. Previewing, a technique that forecasts required input, can help overcome problems low frame rate.

Project members: Ben Watson (NU), Bill Ribarsky (Ga Tech) & Neff Walker (UNICEF).

Sponsors: NSF award 0093172.

Publications

B.A. Watson, N. Walker, P. Woytiuk, W.R Ribarsky (2003). Maintaining usability during 3D placement despite delay (pdf). Proc. IEEE VR 2003 conference, (Los Angeles, March). 133-140.

B.A. Watson, N. Walker, W. Ribarsky & V. Spaulding (1999). Managing temporal detail in virtual environments: relating system responsiveness to feedback (pdf). ACM CHI 99 Extended Abstracts, Human Factors in Computing Systems (ACM CHI 99 Conference), 280-281.

B.A. Watson, N. Walker, W.R. Ribarsky & V. Spaulding (1998). The effects of variation in system responsiveness on user performance in virtual environments (pdf). Human Factors, Special Section on Virtual Environments, 40, 3 (Sept), 403-414.

B.A. Watson, V. Spaulding, N. Walker & M.W. Ribarsky (1997). Evaluation of the effects of frame time variation on VR task performance (pdf). VRAIS '97, IEEE Virtual Reality Annual Symposium (Albuquerque, April, 1997), 38-44.

Imagery

	An experimental view During one task, participants placed this oblong object within a target volume, in a head- and hand-tracked virtual environment.
	Results of latest study Placement times rise as frame rates drop; more steeply if placement difficulty is increased. Previewing allows more reliable performance as frame rates drop and difficulty increases.