This may sound stupid, but how about being able to modify more than just the depth of fog? How about being able to modify it’s height, and width if wanted to?
Ok, i’m no expert on the topic so what i say may be reallly stupid . For the controlling the height idea, i saw an effect in the Cg browser from nvidia that uses vertex and pixel shaders to create fog that is only so high. I guess they call it height fog (kind of a no-brainer name).
About the width, i’m not really sure…i think you can do that by creating volumetric fog, or maybe there is a way to create an effect that controls the width instead of the height
Fog in GL doesn’t really occupy space. For every vertex you submit a fog ‘weight’ is calculated with a given formula.
You can explicitly send your own fog weigths with the GL_EXT_fog_coord extension which has been promoted to core functionality in GL 1.4.
zeckensack’s right. And if you want to implement your own user-defined advanced fog equation, you can use vertex programs (vertex programs were submitted as an ARB extension since OpenGL1.4, just like multitexturing was submitted as an ARB extension in OpenGL1.2.1).