The Influence of Eye-Height and Body Posture on Size Perception in Virtual Reality

This paper investigates the impact of avatar eye-level variation on the perceived size of visual objects in virtual reality (VR) environments. The study utilized an HTC Vive Pro Eye head-mounted display (HMD) and observers assumed three postures: upright, supine, and prone. We investigated the relationship between eye-height and posture difference based on eye-height estimation using two environments, background without texture and background with texture. The experimental results showed that the results were in line with previous studies on the differences in eye-height. As in the previous study, the differences in the background without texture environment and background with texture were also influenced by perception, and it was confirmed that the background with texture environment was greatly influenced by the eye-height estimation. In terms of posture, upright posture was perceived as the largest at 70 and 120 cm, followed by the supine and prone posture, and upright posture was perceived as the smallest at 220 and 270 cm, followed by the supine and prone posture. This suggests that the upright posture is the most sensitive to eye-height information in size estimation, followed by the supine and prone posture.