Simulation Of Dynamic Clouds Based On Fractal Method

Theory of computer graphics and virtual technology have been increasingly developed, people realistic simulation around the world are possible. Towering mountains, lush green forests, rivers and so on can display vivid in people's eyes. In the simulation of the natural environment, the sky is an important area of simulation. If a successful simulation of the sky, may enhance the virtual system more realism. Although some of the environment to the ground as the main content of the landscape, the sky background is a foil, but with the use of object technology and the increasing demand for high quality produce sky background is an inevitable development. Simulate the sky, in fact, the simulation for the sky, cloud, because the basic of all meteorological phenomena, such as, Teenage rain and snow through the cloud to the performance. Purpose of this study lies in the simulated clouds in the sky, to enrich the field of virtual reality simulation of the natural world.In this paper, the choice of cloud model, we use simulation results for a good surface texture fractal method. Simulation of fractal self-similarity of the surface of the natural landscape of great advantage, only to increase the number of iterations can be very complex texture, which is the texture of the surface and cloud features are compared to be. This paper used a typical fractal approach, the mid-point displacement and the Diamond-Square method simulation of the cloud surface texture, and set the texture roughness, cloud roughness and the iteration number and other parameters to control the texture of the clouds, some of the requirements more efficiency requirements on the generation of low or high places can be reduced by reducing the number of iterations or the roughness of manner. Experiment by entering different parameters to analyze the effect of the generated more effect realistic.If the cloud is static, no matter how strong realistic texture, but also gives the feeling of monotony, these method has been rarely used. Instead, some of the methods to achieve dynamic effects, such as particle systems, cellular automata and other methods have been used. This article the simulation of cloud dynamics, the use of a mature Direct3D texture mapping technology, which compared with the traditional method of OpenGL, the main improvement is in terms of speed, the corresponding results in the display also has improved. Specific approach is to first use the method to generate two-dimensional fractal texture image, then use the resulting texture image as a texture map source data, adding moving effect, change the texture roughness and finally realize the effect of cloud flowing. The adoption of this technology greatly simplifies the modeling and the application has a simple light means a lot. Use of fractal technology, and the combination of texture mapping, and make full use of fractal techniques detailed texture mapping and texture characteristics of high speed and efficiency. Although, this method can't described effect of particle collisions at present, but it's still a very good performance overall effect of clouds. The experimental results show that the proposed algorithm for dynamic cloud simulation screen display smooth, simple and fast, efficient and real time features, to meet the needs the dynamic sky background of certain game scene.