Finding a range of perceived natural visual walking speed for stationary travelling techniques in VR

Travelling is one of the significant interactions in virtual reality (VR). Until now, researchers have come up with many Virtual Locomotion Techniques (VLT) to supply natural, efficient and usable ways of navigating in VR while not causing VR sickness. Stationary VLTs are those which does not demand any physical movement from the user to travel in the virtual environment. In order to improve the experience of walking in this VLT, it is essential to show the view transition speed that mimics the natural walking speed of the user. In this paper, we describe a within-subject study that was performed to establish a range of perceptually natural walking speeds while being stationary. In the study, we provided vibrotactile feedbacks behind the ears of the subjects to avoid motion sickness. The subjects were exposed to visuals with gains ranging from 1.0 to 3.0. The slowest speed was the estimated natural speed of the user, and the highest speed was three times faster than this. The perceived naturalness of the speed was evaluated using the self-report. We found the range of the visual gain to be 1.40 to 1.78.