A method for providing fog or fading due to atmospheric effects during computer animation of an image. The method includes determining a lighting value for a scene's or an image's pixels based on the positions of the pixels relative to a light source. The method includes, for each of the pixels, setting a fade in start distance for each pixel measured from a camera location so as to define when fog is added, e.g., when to fade a pixel's color by blending this color with a fog color. The fade in start distances are set based on each pixel's lighting value, whereby pixels with smaller lighting values or shadowed pixels begin to fade first while highlighted pixels fade with greater distances. The method includes adding fog to the image starting at the fade in start distances for each of the pixels and then rendering the image.