Volumetric Fog feedback thread

[SteveElbows]

@SteveElbows;701939

I note a recent addition to the 4.16 github branch:

[Copy] Added VolumetricFogEmissive to ExponentialHeightFogComponent

• Volumetric fog does not yet support precomputed lighting, so this is the only way to get an ambient lighting term
  #rb none
  #jira UE-43984

[CL 3414761 by Wright in 4.16 branch]

Looks like this made it into Preview 2 of 4.16