[PDF][PDF] System lag tests for augmented and virtual environments

C Swindells, JC Dill, KS Booth - Proceedings of the 13th annual ACM …, 2000 - dl.acm.org
C Swindells, JC Dill, KS Booth
Proceedings of the 13th annual ACM symposium on User interface software and …, 2000dl.acm.org
We describe a simple technique for accurately calibrating the temporal lag in augmented
and virtual environments within the Enhanced Virtual Hand Lab (EVHL), a collection of
hardware and software to support research on goal-directed human hand motion. Lag is the
sum of various delays in the data pipeline associated with sensing, processing, and
displaying information from the physical world to produce an augmented or virtual world. Our
main calibration technique uses a modified phonograph turntable to provide easily tracked …
Abstract
We describe a simple technique for accurately calibrating the temporal lag in augmented and virtual environments within the Enhanced Virtual Hand Lab (EVHL), a collection of hardware and software to support research on goal-directed human hand motion. Lag is the sum of various delays in the data pipeline associated with sensing, processing, and displaying information from the physical world to produce an augmented or virtual world. Our main calibration technique uses a modified phonograph turntable to provide easily tracked periodic motion, reminiscent of the pendulum-based calibration technique of Liang, Shaw and Green. Measurements show a three-frame (50 ms) lag for the EVHL. A second technique, which uses a specialized analog sensor that is part of the EVHL, provides a “closed loop” calibration capable of sub-frame accuracy. Knowing the lag to sub-frame accuracy enables a predictive tracking scheme to compensate for the end-toend lag in the data pipeline. We describe both techniques and the EVHL environment in which they are used.
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