Building database applications of virtual reality with X-VRML

A new method of building active database-driven virtual reality applications is presented. The term "active" is used to describe applications that allow server-side user interaction, dynamic composition of virtual scenes, access to on-line data, continuous visualization, and implementation of persistency.The use the X-VRML language for building active applications of virtual reality is proposed. X-VRML is a high-level XML-based language that overcomes the main limitations of the current virtual reality systems by providing convenient access to databases, object-orientation, parameterization, and imperative programming techniques. Applications of X-VRML include on-line data visualization, geographical information systems, scientific visualization, virtual games, and e-commerce applications such as virtual shops. In this paper, methods of accessing databases from X-VRML are described, architectures of X-VRML systems for different application domains are discussed, and examples of database applications of virtual reality implemented in X-VRML are presented.