Research On Generating Technique Of Virtual Ocean Environment And Special Effects

The simulation of the ocean environment has played an important role in the scientific research and project application. People pay more and more attention on how to develop the ocean environment not only has the vivid effect and real time but also can be shared by more simulation objects. According to these demands, the article studies the generating of the virtual ocean environment and special effects based on HLA, a visual platform which has better interaction and reuse ability is provided for the simulation system.Two wave models which are Longuet-Higgins and FFT based on wave spectrum have been formed and simulated. Compared with these two models at the scene's effect and the rate of the frame, the simulation results indicates that the wave model based on FFT has the higher caculation efficiency, and can show the wave's form at all kinds Conditions of the sea.Adding the lighting and the texture effect to the sea surface base on the FFT model, because of the magnitude caculation of the effect's rendering, the Cg technology is used to compile the program for GPU, some caculation is carried out by the GPU, so the CPU's burden is shared. It can both insure the simulation's real time and the picture's reality.For providing a more vivid and thoroughly virtual ocean scene, sky sphere is adopted insteading of sky box to improve the effect of the ocean's sky, at the same time , using the particle system to make the stern wake, also some weather effects such as snow, rain, fog ,night and so on. For the sake of high rate of the frame, there are four measures are adopted: making the use of the FFT's character, eye-point related technology, auto adaptive grid technology, list technology to deal with the particle system to reduce the caculation and improve the simulation's real time. According to the reality's demand of the simulation, a virtual ocean environment is applied to a ship motion simulation system based on HLA, it has some federations which can interact with each other, the virtual ocean enviroment joins the simulation system as one of them, it can receive messages such as the condition of the sea, weather, the movement of the ship which are sended by other federations, and displays the scene real time. It provides a direct platform for the simulation validation, and makes the virtual ocean environment that has a better interaction and reuse ability come to true.