Abstract: ray tracing and meteorological simulation of clouds Complex but interesting model for volume densities such as clouds. Shadows and lighting are both created most realistically. It may not be practical to use their methods in practice however, due to the high overhead of computation. This paper presents new algorithms to trace objects represented by densities within a volume grid, e.g. clouds, fog, flames, dust, particle systems. We develop light scattering equations, discuss previous methods of solution, and present a new approximate solution to the full three-dimensional radiative scattering problem which is suitable for use in computer graphics. Additionally, we review dynamical models for clouds used to make an animated movie.