Development of the Walking-in-place-based VR Locomotion Method Supporting Lateral and Backward Movement

Objective: This study aimed to develop the Walking-in-place-based locomotion method (WIP) that supports lateral and backward movements through gestures.<br/>Background: WIP is one of the most popular VR locomotion method for its naturalness, usefulness, and immersiveness. However, it is limited to forward movement, causing discomfort during precise navigation.<br/>Method: The study consisted of two parts. In the first part, a gesture collection experiment was conducted with 14 participants. They were asked to perform upper and lower body gestures suitable for lateral and backward movements while using WIP. The collected gestures were grouped according to their similarity and representative gesture sets were derived based on the frequency analysis. In the second part, WIP-based locomotion methods which enables lateral and backward movements were developed using the gesture sets. 15 participants navigated a virtual city using the new locomotion methods and evaluated usability, sickness, presence (involvement and adaptation/immersion) using the System Usability Scale (SUS), the Virtual Reality Sickness Questionnaire (VRSQ) and the Presence Questionnaire 3.0 (PQ 3.0).<br/>Results: In the first study, it was concluded that Lateral or Backward Body Leaning (BL) and Keeping One Foot on the Side or Behind the back (KF) as the most appropriate gesture sets for lateral and backward movements. In the second study, two WIP-based locomotion methods, WIP with BL and WIP with KF, scored 73.50 and 77.70 for usability, 4.22 and 5.00 for sickness, 66.26 and 67.53 for involvement, and 44.80 and 48.33 for adaptation/immersion, respectively. There were no significant differences between the two methods for any of the measures.<br/>Conclusion: It was confirmed that WIP with BL and WIP with KF have the potential for use in VR navigation. In particular, WIP with BL was found to have an advantage in terms of ease of switching between movement directions. On the other hand, WIP with KF was found to have the advantage of being able to move using only lower body gestures.<br/>Application: The two proposed locomotion methods can be used in a variety of VR applications that require an immersive VR navigation experience.