Research On Real Time Algorithm Of Viewing Scene In Distributed Navigational Simulation System

There are a lot of concrete and painstaking works to be done for importing distributed interactive simulation (DIS) technology from military field to civil navigational simulation system. In navigational virtual environment, how to simulate various waves in real-time, how to simulate ship's wakes and the phenomenon of nature such as snow, rain and fog in real-time are very pivotal factors to determine whether a navigational simulation virtual environment is successful or not. In this dissertation, the author has done a deep going research on some key technologies used in distributed navigational simulation system and it's visual system. The main contributions of this dissertation are:1 The architecture of distributed navigational simulation system using PC is presented based on the idea of DIS. After analyzing the characteristic of information stream and communication of the system and network communication modes in Windows operating system, UDP protocol and Winsock OCX control are adopted to implement the high-speed network communication of this system.2 According to the basic request on visual system of navigation simulator, the factors such as resolution, refreshing rate, horizontal angle of visual field, complicated degree of visual system, the reality and quality of the pictures are analyzed in details which are should be considered first when choosing the software and hardware platform of navigation simulator. The concrete specifications of visual system of navigation simulator and some feasible methods are presented.3 Based on the analysis of various wave scales and wave spectrums, the wave spectrums in different sea are discretized adaptively. The processed data are used in the simulation model of irregular long crest wave. The unique mesh model and texture mapping technology are adopted to implement the real-time and dynamic simulation of irregular long crest wave.4 After analyzing the formative condition of spray on sea, the sprays are > simulated dynamically in real-time using particle system.5 The simulation ship's wakes is necessary for full-mission navigation simulation system. The dissertation presents a real-time dynamical simulation model of ship's wakes based on particle system and image synthesis.6 According to the characteristic of contour lines in sea chart, the author has analyzed and studied the existing triangular algorithms carefully. Based on these works, the author designs and implements a mixed algorithm based on point insertion and polygon triangular algorithm. The mixed algorithm has been used to create optimal triangular meshes of contour lines and various LOD models. It supplies a shortcut and convenience method to generate the three dimensions scene of a real harbor terrain.7 A simulation model of snow and rain is presented and implemented dynamically in real-time using particle system. It's the first time to simulate snow and rain in the distributed navigation simulation system.