Evaluating Plausible Preference of Body-Centric Locomotion using Subjective Matching in Virtual Reality

Body-centric locomotion in Virtual Reality (VR) involves multiple factors, including the point of view, avatar representations, tracked body parts for locomotion control and transfer functions that map body movement to the displacement of the virtual viewpoint. Understanding the role of these factors in evoking a plausible walking experience using within- or between-subject experimental designs based on questionnaires and/or objective measurements can be time-consuming and challenging due to the interrelated effects of these factors. This study employed the subjective matching method to evaluate the sense of plausible walking experience during body-centric locomotion in VR. Five relevant factors that may affect locomotion experience were identified by analyzing existing studies, i.e., point of view, the avatar appearance, body parts for locomotion control, transfer functions and the coefficients of transfer functions. A virtual locomotion experiment with these five factors based on subjective matching was conducted. Results showed that participants regarded the point of view as the most critical factor for walking experience enhancement, followed by body parts, transfer functions, the coefficients of transfer functions and finally the avatar appearance. Additionally, participants' preferences for different body parts and the coefficients of transfer functions affected the choice of transfer functions. These results could serve as the guidelines for virtual locomotion experience design that involves combinations of multiple factors and can help achieve a plausible walking experience in VR.