Study Of Three-Dimensional Modeling And Visualization Technology On Clouds

Three-dimensional modeling and visualization technology is a new computer technology developed recently,which is interdisciplinary and comprehensive.Its purpose is to express the three-dimensional model of simulation object by computer graphics,image representation and structure information.To create a realistic,interactive and real-time 3D environment for customers.Cloud,as one of the common phenomena of nature,is one of the important signs of the weather forecast,its shape,distribution and movement can effectively reflect the movement,stability,and water vapor content of the atmosphere,so it is very important to analyze the data and information of clouds.In virtual scene,especially in outdoor virtual scene,3D cloud is a very important and necessary part because it improves the third-dimension of the virtual reality.Through researching the cloud modeling and dynamic simulation put forward by the domestic and foreign scholars,we found that the existing algorithms mainly have the following problems:Introduce complex mathematical model and calculation is complex;Almost unable to realize user-defined cloud shape;unable to realize the real time and dynamic simulation of cloud,particularly put realistic simulation in the context,the instantaneity is worse.Aiming at these problems above,this paper realize 3D visualization of cloud based on satellite image and meteorological data independent.Realize 3D visualization of cloud based on satellite images:Extracting the gray value of each pixel in infrared satellite images to inverse the height information of the cloud.To improve the traditional Delaunay triangulation by combining the divide-and-conquer algorithm with the greedy insertion method.And then,to reconstruct the 3D surface of cloud with the improved Delaunay triangulation.At last,realize the simulation of 3D cloud for the cloud in the satellite images.Some comparison has be done between the improved Delaunay triangulation and the traditional Klein algorithm in this paper.With the increase of the number of discrete points,the advantage of the improved algorithm is more significant.Realize 3D visualization of cloud based on meteorological data.To choice the typhoon "Jangmi" in September 2008 as the research object.Jangmi is simulated numerically based on Final Operational Global Analysis provided by American National Centers for Environmental Prediction.To acquire the simulation result data with the interval of one hour.To visualize the simulation results based on Interactive Data Language by using the method of pseudo color,isosurface extraction and volume rendering.At last,realize the 3D simulation of cloud.