<title>Bridge between developers and virtual environments: a robust virtual environment system architecture</title>

Abstract

A new approach is presented to the problems associated with designing and implementing virtual environment applications which supports robust methods of describing and building virtual worlds and interaction techniques. Despite the functional similarities between virtual world and graphical user interface designers, virtual world designers are hindered by a lack of low level support which user interface designers typically get from a toolkit or application framework. Furthermore, a well-defined set of standard interaction techniques and devices has been established for the desktop metaphor which does not exist in the virtual environment arena. The importance of shielding the programmer from the low level details of rendering, network communication, and device software is widely recognized. However, most off-the- shelf virtual reality systems provide only a device polling mechanism through which the entire interface must be built. Polling forces the programmer to delve into the low level details of each device for every interaction technique to be used. We are currently developing a system called the Bridge that is designed to meet the needs and requirements of highly interactive virtual environment applications. The distributed architecture of the Bridge clearly separates the interaction from the application and supports a more efficient, event-driven model. High level descriptions of user-computer dialogues can be easily constructed allowing modification of interaction techniques and styles.