The Research And Design Of Collaborative Virtual Environment

Collaborative virtual environment that integrates various computer technique including virtual reality, network, and computer supported cooperative work provides users with shared virtual space to make people interact and collaborate with others more naturally and harmoniously. It is becoming developmental trend of next generation computing collaboration application, which is being applied to digital entertainment, distance education and simulation of real word gradually.This paper explores concurrency control mechanism and transmission mechanism of interactive information in CVE after summarizing and referring domestic and overseas research achievement about CVE and proposes several feasible new methods. Main research aspects and creative achievements are as follows:1. Concurrency control mechanism in CVE. Following designing principle of concurrency control mechanism in CVE, this paper proposes a concurrency control mechanism based on syncretizing non-mutex operation after comparing current pessimistic and optimistic concurrency control mechanism and gives initial design as well as implementation. This mechanism achieves sound balance in terms of consistency, responsiveness and fairness by adopting real time local operation to guarantee consistency and individual responsiveness, implementing final consistency through confliction dissolution and confirm of concurrency control on server side and replica synchronization.2. Transmission mechanism of interactive information in CVE. To guarantee high efficient and reliable data transmission in CVE, increase network throughput as well as mitigate load of backbone, this paper presents a reliable multicast protocol based on layered structure and error recovery channel. It adopts special channel to execute retransmission to decrease process load of receiver and increase throughput. Cooperators are divided into trunk layer and local layer which limits most of the data transmission in local layer, to fatherly balance process cost and localize error recovery.Finally, this paper designs a prototype system, which proves that concurrency control mechanism and reliable multicast protocol are correct and effective.