I used the map value node which is typical but I dont like how the map value uses the Z pass infinitely in all directions parrallel with the camera. Meaning the fog or mist will have no vertical restirction like fog you might see in the real world. The built in mist has some issues as well and I find I have better results with the map value node method. So as a work around I split the map value output and inverted one and then blurred it quite a bit and the did a color mix “multiply” and recombined the two and then did another color mix “screened” with the render output. I also mixed a solid gray color to darken the fog a bit just before the mix with the render output.
@hotzst - haha I know she is definitely a monkey, I just thought the name was clever and fun:) Glade you liked it though.
Thanks everyone else and Happy Blending!