I am having some problems controlling my distance field volume fog.
My set up is:- Distance to object minus desired height of fog. I one minus this and then divide it by a soft edge value. This then gets multiplied by a noise and fed into the extinction value in the volume material
What I cant figure out is how the check against the vertex normals creating the distance field on the xy plane so i can multiply against them to control or reduce the field controlling the fog. I cant see where I would get the 3d value to query against.
I also would like to multiply the whole volume against a ramp volume made of texture ramps and normalised bounding box, so I can control the fade out of the volume better.