Design and evaluation of a visual acclimation aid for a semi-natural locomotion device

One of the limitations of most virtual reality (VR) systems is that users cannot physically walk through large virtual environments. Many solutions have been proposed to this problem, including locomotion devices such as the Virtusphere. Such devices allow the user to employ moderately natural walking motions without physically moving through space, but may actually be difficult to use at first due to a lack of interaction fidelity. We designed and evaluated a visual aid that shows a virtual representation of the sphere to the user during an acclimation phase, reasoning that this would help users understand the forces they were feeling, plan their movements, and better control their movements. In a user study, we evaluated participants' walking performance both during and after an acclimation phase. Half of the participants used the visual aid during acclimation, while the other half had no visual aid. After acclimation, all participants performed more complex walking assessment tasks without any visual aid. The results demonstrate that use of the visual aid during acclimation was effective for improving task performance and decreasing perceived difficulty in the assessment tasks.