Unlike alpha blending, fogging, which is intended to create a fog effect, incorporates depth information into the calculation, increasing the depth effect. A fogging graphic takes into account how far an object
is in space.
thathave no spatial depth are therefore unclouded, whereas pixels that are deep in space have a strong clouding.
In fogging, represented by a gray fog color, alpha blending increases continuously. Pixels farther away from the viewer are grayer, pixels closer to the viewer are less gray.
Depth cueing, or depth shading, is a technique similar to fogging, with the difference that in depth cueing the fade is to black, rather than white as in fogging.