Fast Modeling of Realistic Clouds

Computer generated clouds are indispensable in virtual environments nowadays. This paper proposes a probability fields controlling cellular automata method. Creation of the probability fields adoptes fractional Brownian motion (fBm) which accords with the natural chaotic motion of particles and endows the results with realistic cloudy characteristics. We accelerate our simulation by running all the modeling procedures on the programmable graphics hardware. The illumination model accounts for the sunlight and background lights with single scattering model. We use ray casting technique to render 3D realistic clouds. Integration of our results into virtual terrain environment enhances the reality of the scene. The total virtual environment is rendered at interactive frame rates.