A Controllable Method for Animation of Earth-scale Clouds

Computer generated images of the earth are often used for space flight simulators, computer games, movies, and so on. Clouds are indispensable to the creation of realistic images in these applications. This paper proposes a method for animating clouds surrounding the earth. The method allows the user to control the motion of clouds by specifying the center positions of high/low atmospheric pressure areas on the earth’s surface. This data is used as input data and a three-dimensional velocity field is then calculated by solving Navier-Stokes equations. Water vapor is advected along the velocity field. Clouds are then generated due to the phase transition from water vapor to water droplets. We also propose an interactive system that enables the user to interactively control the simulation. The final photorealistic images are rendered by taking into account optical phenomena such as the scattering and absorption of light due to cloud particles.