This is fully Volumetric fog. You can increase reselution if you want. I would suggest lowering the resolution for a higher FPS, since this lowers mine to 1... I found that you could use layered faces in all directions to be able to create a fog effect. This is very heavy on the CPU, so if you know of any better way of doing this, with the same HD effect, please comment and call me an idiot. Well, enjoy your foggy day.