Implementation of mechanisms for concurrent 3D design and visualisation

To perform 3D editing in a cooperative environment presents problems that do not exist in other environments. Maintaining the consistency among all the replicated instances of the scene being edited is the key problem. The authors present the mechanisms to solve these problems such as collaborative operations on multiple scenes, cooperative copy and paste operations, and the ability of reversing actions (undo) in a cooperative editing environment. A brief introduction to a cooperative 3D editing and visualisation tool is presented. The protocol to ensure its memory consistency is discussed. The data structures, as well as the techniques used to manipulate the data to realise the mechanisms are described