I'm trying to find something for 2.8 but struggling.
I want to use the z height (depth on render layer?) to reduce the intensity of mist (composite layer) exponentially as height increases.
Currently, the mist render layer setup only affects intensity based on distance from camera.
The following tut shows how it could be done but it doesn't seem to have the same effect in 2.8.
Can anyone help with the node setup please?