This paper describes the results of a study conducted to determine the efficiency of visual cues for a collaborative navigation task in a mixed-space environment. The task required a user with an exocentric view of a virtual room to navigate a fully immersed user with an egocentric view to an exit. The study compares natural hand-based gestures, a mouse-based interface and an audio only technique to determine their relative efficiency on task completion times. The results show that visual cue-based collaborative navigation techniques are significantly more efficient than an audio-only technique.

This paper presents a new interaction metaphor for mixed space collaboration: HOG on a WIM. Hand of god (HOG) on a world in miniature (WIM) is the first collaborative WIM. It enables a table-top display user to collaborate with a virtual reality (VR) user. The tabletop display user has a god's eye view of the virtual world and communicates with the VR user through natural gestures and speech. The VR user controls a WIM to navigate and manipulate the virtual world with the aid of the tabletop display user's guidance.

This paper presents a new interaction metaphor we have termed "god-like interaction". This is a metaphor for improved communication of situational and navigational information between outdoor users, equipped with mobile augmented reality systems, and indoor users, equipped with tabletop projector display systems. Physical objects are captured by a series of cameras viewing a table surface indoors, the data is sent over a wireless network, and is then reconstructed at a real-world location for outdoor augmented reality users. Our novel god-like interaction metaphor allows users to communicate information using physical props as well as natural gestures. We have constructed a system that implements our god-like interaction metaphor as well as a series of novel applications to facilitate collaboration between indoor and outdoor users. We have extended a well-known video based rendering algorithm to make it suitable for use on outdoor wireless networks of limited bandwidth. This paper also describes the limitations and lessons learned during the design and construction of the hardware that supports this research.