Night fill (hemisphere) light intensity.
Suggested toneMappingExposure (unsmoothed).
Horizon sky radiance, averaged around the compass (use as fog colour).
Aerial perspective 0..1: 1 in the troposphere, fading to 0 at the Kármán line (space has no haze).
Moonlight colour.
Moonlight intensity.
0 by day … 1 at night.
Zenith sky luminance.
Sunlight colour after the atmosphere.
Sunlight intensity (0 below the horizon).
Lighting derived from a sky state. All colours are linear RGB normalised to a max of 1.