On Constructing an Open Architecture for Virtual Space on the Www

Recently, there are many virtual spaces on the Internet, which may contain avatars and objects. In general, avatars and objects which users can use in a virtual space have the restrictions in their locations because the mechanisms to control them are embedded in each virtual space system. Moreover, a user cannot move those objects and avatars to another virtual space, i.e., operating one avatar in several di erent spaces, or let it carry objects to another virtual space. Aiming at realizing the integrative use of several avatars and objects in virtual spaces, in this paper, we propose the open cyberspace architecture (OCA), where we de ne an HTTP-based protocol in various virtual space systems, object servers, and clients to exchange visual information of avatars and objects. OCA allows users to move from a virtual space to another using a single avatar and possibly carrying some objects. As a result, OCA enhances the reusability of avatars and objects and, at the same time, the availability of virtual spaces.