Rendering cloudy skies by a volume texture

In order to render clouds and represent the distribution of the Light under a cloudy sky a new rendering method for cloudy skies is introduced. In our new method, clouds are represented by a layer called C layer. Three attributes named transparence, reflection and shadow parameter, are additionally defined at each point of the C layer, and these attributes are used to simulate the translucence and the shading effects of clouds. The atmospheric aerosol such as haze or fog is assumed to have a uniform density under the C layer, and introduce an efficient approach to calculate the scattering coefficient by the haze at different densities according to the vision range.