Scene-Graph-As-Bus: Collaboration between heterogeneous stand-alone 3-D graphical applications

We describe the Scent-Graph-As-Bus technique (SGAB), the first step in a st aircase of solutions for sharing software components for virtual environmen ts. The goals of SGAB are to allow, with minimal effort, independently-desi gned applications to share component functionality; and for multiple users to share applications designed for single users. This paper reports on the SGAB design for transparently conjoining different applications by unifying the state information contained in their scene graphs. SGAB monitors and m aps changes in the local scene graph of one application to a neutral scene graph representation (NSG), distributes the NSG changes over the network to remote peer applications, and then maps the NSG changes to the local scene graph of the remote application. The fundamental contribution of SGAB is t hat both the local and remote applications can be completely unaware of eac h other; that is, both applications can interoperate without code or binary modification despite each having no knowledge of networking or interoperab ility.