event propagation with counting of incoming routes for every node

摘要

A data processing apparatus having a processor coupled to one or more storage divisions may be operable to manipulate data stored therein. When data is formed into a plurality of nodes 68, 70, 76 interconnected with specified relationships between the input and output fields of the selected node, The event is processed accordingly. To avoid dependency problems where two or more nodes are routed to the input field of the same node, each node routed to or from the node is associated with a count field 74 that maintains the number of ingress paths to that node And a notification structure 72. The device is particularly suited for configuration as a virtual environment data browser for flexible VRML and similar environments and the nodes are interconnected data resources of the environment.