Terrain Fog questions

I was just wondering if anyone knew exactly how this works.
The more I experiment expecting to find some kind of pattern, the more I get confused. I am rather new to map-making so this tends to happen quite a bit.

Apart from just understanding how the system works, what I'm really trying to do is create a fog layer the encompasses the entire floor level, but not cliffs. Think FFIX or LBA2 style. I'm trying to create an 'ocean' of fog and the mountains would basically be the 'islands'.
In doing so, the floor level would be invisible. I've achieved some similar results where it looks right, but when I move down to the floor level it comes back into view, albeit darkened by the fog but not hidden.

To my knowledge this can't realy be done, I asked a similar question a few days ago and got no answer. Some testing I've done however points to the fog being attached to the camera ( which is why it can't work how you want).

Picture a box that always faces the camera and is always the same distance from the camera the Z-Start is the distance from the camera, the Z-End is the side of the box furthest from the camera the fog is most transparent at the start of the box and completely opaque ,except for glowing effects at the end of the box.

The density seems to do nothing, any values above 0 seem to be the same, and any of the exponential options seem to just flood the map

Yea, that's pretty much what I've learned from toying with it.
Thanks for your answer though, Spectralist.

If anyone can prove us wrong, that'd be cool.

Unfortunately, blizzard has said that for performance reasons, you are limited to a single environmental fog type per large grid square in WE. Worse, that is the *minimum* size of a piece of fog as well, so you don't have a lot of fine control over laying fog down.

Keep in mind that environmental fog is different than cinematic fog. The former is something you place in regions, while the latter is something that is applied to your camera. One suggestion is to go to the forum search page, and search for the keyword fog*. I've contributed to a thread by someone seeking to create exactly the same effect you're trying to do, about 6 months ago. You might want to read what we'd talked about then. There are almost certainly ways to create the effect you want, but unfortunately, probably no *easy* ways. One suggestion is to use enviromental fog, and make sure your cliffs are all created along the borders of the large grid squares. That way, you can ensure that all fog is on the "lowlands" without any spilling onto the "highlands".