Abstract
Interaction is the primary characteristic of a Virtual Environment and update rate is normally taken as an index or measure of the interactivity of the system. The speed of many systems is dictated by the slowest component which is often the Computer Image Generator (CIG). It is common for the workload of the CIG to vary and hence the performance of the system. This paper shows how a variable update rate can produce undesirable results. Two solutions to this problem are presented: service degradation and worst-case. In the case of the CIG, service degradation would require the quality of the image to be reduced such that the time taken never exceeds a given deadline. The worst-case technique works by finding the longest time taken to render any view and then uses that as the deadline for completion. The support of predictive methods is one of several benefits of this approach. An implementation of the worst-case technique is described which takes finer control over the CIG than usual and may be applied to many existing systems with little modification.
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Hawkes, R., Rushton, S. & Smyth, M. Update rates and fidelity in virtual environments. Virtual Reality 1, 99–108 (1995). https://doi.org/10.1007/BF02009726
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DOI: https://doi.org/10.1007/BF02009726