VRML event propagation with input path count for each node

摘要

A data processing apparatus comprising a processor coupled with one or more storage devices is operable to manipulate data stored therein. Where the data is in the form of a plurality of nodes (68, 70, 76), with interconnect relationships specified between selected node input and output fields, event handling in relation to the nodes is by propagation of an event cascade through the node interconnections. To avoid dependency problems where two or more nodes route to the input field of the same node, each node routed to or from has an associated notification structure (72) in a field (74) of which a count is maintained of the number of incoming routes for that node. The arrangement is particularly suited for configuration as a virtual environment data browser for VRML-compliant and similar environments where the nodes are interconnected data assets of the environment.