An multiuser Undo/Redo method for replicated collaborative modeling systems

Undo/Redo can help rolling the whole system back to some previous state. However, many group Undo/Redo researches are based on co-edit system of text object. This paper firstly addresses the Undo/Redo in 3D collaborative solid modeling system. After analysis of the existing Undo/Redo method, this article proposed a multiuser Undo/Redo method in replicated collaborative modeling system. The implementation of the Undo/Redo operation in both local site and remote site is described in detail respectively. In our method, the user´s intention can be preserved. The preservation is based on dependency relationship among users at different sites. The proposed approach has been tested in a prototype system with case study.