Direct incremental transmission of boundary representation

The real-time transmission of the boundary representation (B-rep) is necessitated by collaborative design. However, it is difficult since the B-rep is very complex and the current network bandwidth is limited. Incremental transmission, which can significantly decrease the data to be delivered, makes it possible to transmit the B-rep in real time during collaborative design.In this paper, we propose an approach to direct incremental transmission of the B-rep over Internet. The algorithm consists of three steps: Identify and encode the incremental model of the B-rep once a modeling operation is performed; Then, transmit the incremental model as well as the related geometric information to other remote site; Finally, decode the received codes of incremental model and directly embed the restored entities into the local B-rep. The traits of the approach lie in: (a) The incremental B-rep is identified, transmitted and restored completely based on the B-rep data structure without the support of any other auxiliary model; (b) Topological entity hierarchy chain is put forward to enable the simple and direct recovery of the transmitted incremental B-rep.