Lane Phillips

Distance perception in NPR immersive virtual environments, revisited

Numerous previous studies have suggested that distances appear to be compressed in immersive virtual environments presented via head mounted display systems, relative to in the real world. However, the principal factors that are responsible for this phenomenon have remained largely unidentified. In this paper we shed some new light on this intriguing problem by reporting the results of two recent experiments in which we assess egocentric distance perception in a high fidelity, low latency, immersive virtual environment that represents an exact virtual replica of the participant’s concurrently occupied real environment. Under these novel conditions, we make the startling discovery that distance perception appears not to be significantly compressed in the immersive virtual environment, relative to in the real world.

Redirecting Walking and Driving for Natural Navigation in Immersive Virtual Environments

Walking is the most natural form of locomotion for humans, and real walking interfaces have demonstrated their benefits for several navigation tasks. With recently proposed redirection techniques it becomes possible to overcome space limitations as imposed by tracking sensors or laboratory setups, and, theoretically, it is now possible to walk through arbitrarily large virtual environments. However, walking as sole locomotion technique has drawbacks, in particular, for long distances, such that even in the real world we tend to support walking with passive or active transportation for longer-distance travel. In this article we show that concepts from the field of redirected walking can be applied to movements with transportation devices. We conducted psychophysical experiments to determine perceptual detection thresholds for redirected driving, and set these in relation to results from redirected walking. We show that redirected walking-and-driving approaches can easily be realized in immersive virtual reality laboratories, e. g., with electric wheelchairs, and show that such systems can combine advantages of real walking in confined spaces with benefits of using vehiclebased self-motion for longer-distance travel.

A little unreality in a realistic replica environment degrades distance estimation accuracy

Users of IVEs typically underestimate distances during blind walking tasks, even though they are accurate at this task in the real world. The cause of this underestimation is still not known. Our previous work found an exception to this effect: When the virtual environment was a realistic, co-located replica of the concurrently occupied real environment, users did not significantly underestimate distances. However, when the replica was rendered in an NPR style, we found that users underestimated distances. In this study we explore whether the inaccuracy in distance estimation could be due to lack of size and distance cues in our NPR IVE, or if it could be due to a lack of presence. We ran blind walking trials in a new replica IVE that combined features of the previous two IVEs. Participants significantly underestimated distances in this environment.

Redirected Steering for Virtual Self-Motion Control with a Motorized Electric Wheelchair

Redirection techniques have shown great potential for enabling users to travel in large-scale virtual environments while their physical movements have been limited to a much smaller laboratory space. Traditional redirection approaches introduce a subliminal discrepancy between real and virtual motions of the user by subtle manipulations, which are thus highly dependent on the user and on the virtual scene. In the worst case, such approaches may result in failure cases that have to be resolved by obvious interventions, e. g., when a user faces a physical obstacle and tries to move forward. In this paper we introduce a remote steering method for redirection techniques that are used for physical transportation in an immersive virtual environment. We present a redirection controller for turning a legacy wheelchair device into a remote control vehicle. In a psychophysical experiment we analyze the automatic angular motion redirection with our proposed controller with respect to detectability of discrepancies between real and virtual motions. Finally, we discuss this redirection method with its novel affordances for virtual traveling.