UBC Theses and Dissertations
3D task performance using head-coupled stereo displays Arthur, Kevin W.
"Head-coupled stereo display" refers to the use of a standard graphics workstation to display stereo images of three-dimensional scenes using perspective projections defined dynamically by the positions of the observer's eyes. The user is presented with a virtual scene located within or in front of the workstation monitor and can move his or her head around to obtain different views. We discuss the characteristics of head-coupled stereo display, the issues involved in implementing it correctly, and three experiments that were conducted to investigate the value of this type of display. The first two experiments tested user performance under different viewing conditions. The two variables were (a) whether or not stereoscopic display was used and (b) whether or not head-coupled perspective was used. In the first experiment, subjects were asked to subjectively rank the quality of the viewing conditions through pairwise comparisons. The results showed a strong acceptance of head-coupled stereo and a preference for head-coupling alone over stereo alone. Subjects also showed a positive response to head-coupled stereo viewing in answers to questions administered after the experiment. In the second experiment, subjects performed a task that required them to trace a path through a complex 3D tree structure. Error rates for this task showed an order of magnitude improvement with head-coupled stereo viewing compared to a static display, and the error rates achieved under head-coupling alone were significantly better than those obtained under stereo alone. The final experiment examined the effects of temporal artifacts on 3D task performance under full head-coupled stereo viewing. In particular, the effects of reduced frame rates and lag in receiving tracker data were investigated. The same path tracing task was performed under a set of simulated frame rate and lag conditions. The results show that response times of subjects increased dramatically with increasing total lag time, and suggest that frame rate likely has less impact on performance than does tracker lag.
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