To Support Human-Human Interaction in Collaborative Feature-Based CAD Systems

This paper discussed several key issues for human-human interaction in a collaborative CAD system. The first issue is to track the changing history of topological entities of a part model. A tree-like structure TES_Tree is adopted to record the tracking results in different topological entity changing scenarios. The second issue is the consistency maintenance mechanism in different topological entity variation situations. The third issue is the group Undo/Redo policy for error recovery which is important to eliminate errors propagated to every collaborative site.