Effects of tracking scale on user performance in virtual reality games

We explore how scaling a user's tracking data may impact performance in an immersive virtual reality game, which may have implications for fairness and accessibility of many applications. In our study, which used an HTC Vive room-scale VR system, users play the role of a factory worker who must remove deformed bread from a production line. Users were scaled to a reference height, such that taller than average users were rendered shorter and had shorter reach and shorter than average users were rendered taller and had longer reach than normal. Users also performed with unscaled tracking data. Our analysis indicates that there was no systematic advantage of being taller or shorter than normal, and scaling users may have had a detrimental effect. Moreover, scale changes were noticed by many users who had conflicting preferences for various application-specific reasons, indicating that application strategy can be affected by scale. Results suggest that while virtual reality tracking data may be scaled to compensate for user differences in physical height or reach, care must be taken to ensure that performance will benefit.