Real-time spatial data management for scalable networked augmented virtualspaces

This paper proposes a new framework of managing virtual spaces based on spa tial databases as an extension of VRML-based systems. The framework is suit able for treating continuous virtual spaces and for managing the quality of service (QoS) of the virtual spaces depending on user's operations and sit uations of computer resources. Levels of detail (LoD) of 3D objects is the most important rule for rendering scenes dynamically while managing the QoS . This paper describes a method of managing the QoS depending on the LoD in the form of spatial queries. An advantage of the framework is that spatial databases can incrementally construct virtual spaces in clients using diff erential descriptions based on VRML, that is, DVRML, proposed in this paper . Dynamic spatial data such as avatar's movement and real-time multimedia d ata such as videos should be shared by all participants in a virtual space in real time. Our framework can also handle dynamic spatial data by means o f real-time updating of some spatial objects in spatial databases as well a s static spatial data. We developed some experimental applications based on the framework in order to prove that it is feasible for networked virtual spaces with video components.