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.