The Design And Implementation Of Distributed Virtual Environment Based On WTK

Distributed Virtual Environment (DVE) lets multi-users that maybe located in different places to share information through the network, interact with each other and perform dynamic simulation. Now DVE is a hot topic in both scientific research and engineering development, which also has been widely applied in many fields such as military, collaborative design, distance education, network game etc. It's really a hard work to develop a DVE system due to its complexity in technique. WTK is an advanced professional software kit specially used to develop virtual reality applications. WTK also supports DVE.In this dissertation, through the study of DVE system architecture and relevant knowledge, a distributed navigation simulation system is designed and implemented based on WTK. It supports multi-users to navigate in real time and perform dynamic interaction in a shared 3D virtual world. After the evaluation of traits in DVE architecture and the development environment, in data model, the replicated structure and unified local database are used;in network topology model, a peer-to-peer structure is used. The system design is conducted as functional component, the framework and relationship between components are clearly presented. Network communication component uses UDP/IP and multicast to implement the transmission of message in real time. Session management component uses group member control solving the join and leave of users when system is on run, maintaining the consistency of group information. Users can participate in the VE as an avatar through role assignment. Virtual world management component introduces scene graph to make an effective maintenance of virtual world database, state update message is used to keep the consistency in virtual world. Man-machine interaction component uses mouse to control the movement of viewpoint to navigate the virtual world, keyboard is used for some special interaction functionality. At the end of this dissertation, a system test is executed from the view of system function and system performance, the test results show the correctness of the system design.It's a good attempt to develop DVE system using WTK, the design and detailed implementation presented in this dissertation are useful and meaningful for DVE development, and it's a good platform for future study of DVE technology.