AR2Hockey: a case study of collaborative augmented reality

This paper introduces a collaborative augmented reality (AR) system for realtime, interactive operations. AR enables us to enhance physical space with computer generated virtual space. In addition, the collaborative AR makes multiple participants to simultaneously share a physical space surrounding them and a virtual space, visually registered with the physical one. They can also communicate each other through the mixed space. This paper describes an AR2Hockey (Augmented Reality AiR Hockey) system where players can share a physical game field, mallets, and a virtual puck to play an air-hockey game, as a case study of collaborative AR system. Since realtime, accurate registration between both spaces and players is crucial for the collaborations, a video-rate registration algorithm is implemented with magnetic headtrackers and video cameras attached to optical see-through HMDs. The configuration of the system and the details of registration are described. Our experimental collaborative AR system achieves higher interactivity than a totally immersive collaborative VR system.