CompuServe Messages

The effect volumetric lighting simulates is seen in real life when there's enough atmosphere to "show" the light beam – spot lights at a smokey rock concert is a perfect example. When an object, say the musician, steps in the beam of light a shadow is cast down the "volume" of the light cone. Raising an open hand up into the beam would cause 5 "streaks" of shadow as the fingers encroach which form into one broad streak as the hand raises higher. That's volumetric lighting – rarely needed but definitely an impressive effect.