Pointing in the third-person: an exploration of human motion and visual pointing aids for 3D virtual mirrors

Abstract

A “virtual mirror” is a promising interface for virtual or augmented reality applications in which users benefit from seeing themselves within the environment, such as serious games for rehabilitation exercise or biological education. While there is extensive work analyzing pointing and providing assistance for first-person perspectives, mirrored third-person perspectives have been minimally considered, limiting the quality of user interactions in current virtual mirror applications. We address this gap with two user studies aimed at understanding pointing motions with a mirror view and assessing visual cues that assist pointing. An initial two-phase preliminary study had users tune and test nine different visual aids. This was followed by in-depth testing of the best four of those visual aids compared with unaided pointing. Results give insight into both aided and unaided pointing with this mirrored third-person view, and compare visual cues. We note a pattern of consistently pointing far in front of targets when first introduced to the pointing task, but that initial unaided motion improves after practice with visual aids. We found that the presence of stereoscopy is not sufficient for enhancing accuracy, supporting the use of other visual cues that we developed. We show that users perform pointing differently when pointing behind and in front of themselves. We finally suggest which visual aids are most promising for 3D pointing in virtual mirror interfaces.