Emulation System Of Climate Based On Clouds

With the development of theory and technology of computer graphics, people focus their attention from the real world to our virtual world. And people are tring to emulate the real world step by step. Though it is hard as we can imagine, the development of computer science make it possible to present the real world in the cirtual world in some aspects. This paper aims at modeling the natural phenomenon in the sky, during which the cloud takes the leading place. With no doubt, this work will enrich the virtual world.In modeling part, this paper models the process of formation of clouds from water vapor. This paper proposes a methold of Noise based on fractal for modeling clouds. And the distribution of clouds is presented in the form of voxel, using the methold of fractual and controled Perlin noise. When this paper uses Perlin noise, there is some control on the total distribution of clouds. The expression of clouds in the form of voxel is base on the physical distribution according to the envirment prosperities. So from the angle of clouds physics, it is fairly suitable for displaying the details of clouds and easy in redering process. This methold not only sounds well in presenting the detailed clouds, but also supported authenticity for the modeling process.In render part, this paper introduces backward multiple scattering based on forward multiple scattering. And this paper proposes a model of self-adapting method of global scattering for calculation scattering. In former model of redering clouds, people always just consider forward multiple scattering. While in this paper, it considers some special enviroment during which the effect of backward scattering cannot be neglected. Also it makes the process of transforming from usual enviroments to special enviroments smooth. Additonally, this paper improved the algorithm in the implementation of rendering methold. This paper devides the single pipleline of caculating multiple scattering into two pipepline: one for caculating outcoming desity, the other for income density.Finally, this paper realizes a framework for skies realism: transfer the voxel data as the uniform format between the simulator module and the render module with the uniform interfaces. This framework makes the skies realism easier to expand and convenient to the continued research.