Patent ID: 6538651
Filing Date: 2003-03-25
Classification: G06T,H04N

Abstract:
A method of computer aided 3D modelling of geometric objects undergoing changes wherein a directed acyclic graph is executed to generate a 3D model by a computer system, the directed acyclic graph including a plurality of nodes which are connected each other with other nodes with directed edges between two nodes, each node representing a modelling operation of the geometric objects and each directed edge indicating the direction of flow of data from one node to another, comprising steps of:one of the plurality of nodes sending a change event indication specifying a type of change to at least one other node along an associated directed edge, upon receiving the change event indication, each of the receiving other nodes determining based on preset rules if the received change event indication will result in change in its output data, and each node in succession sending a further change event indication to succeeding nodes when it determines that the received change event indication will result in change in its output data.