INFLUENCES OF FOCAL LENGTH ON SPACE PERCEPTION IN A VIRTUAL REALITY ENVIRONMENT

Abstract

In recent years, VR techniques have been applied in various fields, and communication in VR spaces has become increasingly common across a variety of situations. Moreover, it has been reported that personal space plays an important role in VR environments as well. The size of personal space varies between individuals depending on various factors, such as gender, personality, and others. In other words, even if one person feels that the communication distance with another person is "favorable," the other person may perceive this distance as "unfavorable". Based on this fact, we have proposed a communication environment in VR space that satisfies the personal space requirements of both individuals without altering the physical distance between them. Specifically, we developed a screen display method that changes a user’s perceived distance to others by adjusting the focal length of the camera in the VR environment. In this study, we investigate the effects of the proposed method on information transmission within VR space. The experimental results indicate that when a user's personal space is large, it is desirable to adjust the camera’s focal length to a shorter value (thus making the apparent distance appear longer). Conversely, when a user's personal space is small, it is preferable to adjust the camera’s focal length to a longer value (making the apparent distance appear shorter). Furthermore, the results showed that, in terms of information transmission and distance perception, participants in the large personal space group tended to give higher ratings for a focal length of 15 mm, while participants in the small personal space group tended to give higher ratings for a focal length of 75 mm.