Managing dynamic shared state in virtual space for collaborative design

When building the virtual world for distributed collaborative design, the senses of sharing the world and cooperation between physically distributed hosts and users are usually achieved by a maintained dynamic shared state. So that those events that happen in another physical location can be virtually "seen" by other participants, communication through a network is indispensable. Because of the limited network bandwidth and limited CPU resources reserved for communication in a virtual world simulation, reducing communication traffic is a critical issue. We present an efficient model, the improved "lazy model", to reduce communication for maintaining the dynamic shared state. We also propose an approximate method using AOI, area of interest, to enhance the implementation of this model.