关键词: 体积云, 气象数据, 高度相关函数, 多噪声, 光照模型

Abstract: In order to build a realistic simulation environment in the smart drone swarm simulation system,it is necessary to consider modeling and rendering clouds based on weather data.At present,cloud simulations based on real weather data generally adopt physical modeling methods,such as solving NS equations and particle system,which are burdened by heavy calculus equation solving tasks,so they have the disadvantages of large computational volume and inability to achieve real-time simulation in large-scale scenarios.Aiming at this problem,a method of modeling volumetric cloud is proposed.Firstly,weather data is used to generate a texture,then combined with the height dependent functions to define changes in the shape and density of clouds in height,and finally the cloud is modeled in combination with multi-noise.So the weather data is effectively combined with non-physical modeling methods.In the rendering,the color and transparency of each sample point are calculated by using raymarching algorithm to accumulate the density of the cloud from the line of sight direction and the sun,in combination with the law of light absorption and scattering,and finally the cloud is drawn.Experiments show that the simulated volumetric clouds are consistent with the cloud information in the weather data,highly efficient,and close to the real cloud in terms of shape and color.

Key words: Volume cloud, Weather data, Height dependent functions, Multi-nosie, Light model