Layer fog?

Does anyone here know how to do layer fog, like in Quake 3 (fog of death, or whatever thats called)? I know how to do general fog, of course, but layer fog? Is it just a blended quad over the foggy area, and then normal fog when the player is in the fog? Or is it a start / end calculation based on where the layer starts?

Some time ago there was exactly your question discussed here…
Try a search…


Search for “Volumetric fog problems”

Thanks. I’ll check that out.