Evaluating Cybersickness of Walking on an Omnidirectional Treadmill in Virtual Reality

Abstract

Cybersickness is a type of motion sickness that may occur during a virtual reality (VR) experience. Many studies have proposed solutions to mitigate cybersickness, while navigating a virtual environment with controllers or walking over a floor. However, reducing the levels of cybersickness while physically walking on an omnidirectional treadmill has been largely overlooked. In this article, we performed a within-subject study, where 34 novice participants underwent four visual conditions while walking in a virtual maze over an omnidirectional treadmill. In the control condition, the movement speed was reduced of the half compared to a standard navigation speed, a movement speed smoothing was added, and the user’s virtual body was represented. The other three conditions changed one of the visual parameters of the control condition: in the standard speed condition, the speed reduction was not performed; for the no smoothing condition, the smoothing was not performed; and for the no avatar condition, the user’s avatar was removed. Results showed that the standard speed condition was reported to induce a significant level of cybersickness compared to the control and no avatar conditions. Nevertheless, standard speed was also the condition most preferred to navigate a virtual environment. This suggests the need to find a tradeoff between the easiness to move quickly in a virtual environment and the cybersickness that can be induced. We provide a discussion of the obtained results and their implications for the design of VR experiences while users walk upon an omnidirectional treadmill.