I know this is a rather old post so I'm kinda slow in finding it. I find mr. baggins' fog atmosphere settings advice to be VERY useful and it works like it's supposed to (perfectly). However, that being said, I would like to ask for a small amount of advice for a possible modification setting. What I'm trying to accomplish is almost pretty much what's been outlined which is a fog/myst that covers the ground at a depth I can specify in the node parameters but with one exception. I would like to have the fog to have a clear circular area in the center where I can have my Poser character standing unobscured by the fog. I want the fog to be seen as seeming to creep inwards toward them as it engulfs the area around them and is closing in on their position. Is there some sort of transparency that can be added that could accomplish the circular region of "no fog area" that won't be looking too perfectly round at the eges but have a cloudy gradient between the denser are and the clear area?