Evaluating virtual reality locomotion interfaces on collision avoidance task with a virtual character

We have evaluated four locomotion interfaces, namely natural walking (NW), omnidirectional treadmill (OT), walk-in-place (WiP), and joystick (JS). In this within-group study, an avoidance movement task with a virtual character was performed by all participants for each examined interface. Our study considers that natural walking is the most realistic method for navigating in a virtual environment and explores the differences across the examined locomotion interfaces by collecting avoidance movement measurements (clearance distance, trajectory length, and trajectory curvature) and self-reported subjective ratings (simulation sickness, usefulness, satisfaction, ease of use, and task load). The results suggest that, despite the fact that the avoidance movement measurements of the WiP, JS, and NW interfaces share similarities, they, more often than not, differ from the measurements of the OT interface, which makes the OT interface unable to provide precise avoidance movement data for our participants. Moreover, the OT interface was rated lower by participants in terms of learning, usability, efficacy, satisfaction, physical demand, and effort. Our study shows that NW, OT, WiP, and JS as locomotion interfaces present several benefits and drawbacks concerning their application in avoidance movement behavior tasks with a virtual character.