Volumetric fog is awesome but there’s quite a lot of banding, especially when you start playing with post-processing colour corrections. It really destroys the fidelity of the final image IMHO. It seems to me there is a solution out there by using blue noise, enabling very soft transitions and greatly minimising banding. Playdead’s ‘Inside’ is a great example of using blue noise with lots of subtle fog gradients and no banding. Here’s a GDC presentation on how they went about implementing it:
I feel it would greatly enhance UE4’s volumetric fog and make it more versatile.