Fog and atmosphere

Found in the Height Fog and Volumetric Sky categories on BP_DynamicVolumetricSky.

Height fog

Setting	What it does
Height Fog Max Opacity	Maximum density. 1 is thick pea-soup; 0.3 is subtle haze.
Height Fog Falloff Multiplier	How quickly fog thins with altitude.
Height Fog Falloff Per Period	Per-period override of falloff (so dawn can be foggier than noon).
Height Fog Start Distance	Distance from camera before fog kicks in. Useful to keep close-up surfaces clear.

Volumetric fog

Setting	What it does
Enable Volumetric Fog	Master toggle. Required for any “Volumetric Scattering” setting (sun shafts, sky-light scattering) to do anything. Costs performance.
Volumetric Fog Scattering Distribution	Range −1 to 1. Negative is backscatter (sun behind objects glows around them); positive is forward-scatter (sun rays beam outward).
Volumetric Fog Extinction Scale	How quickly light is absorbed in fog. Higher is darker, denser feel.

Caution

Without Enable Volumetric Fog on, every “Volumetric Scattering” setting across the system (sun, sky light, interior overrides) does nothing. If you expected god-rays and got none, check this toggle first.

Volumetric sky

Setting	What it does
Volumetric Sky Sun Area	Size of the sun’s halo within the volumetric atmosphere.
Volumetric Sky Start Distance	Where the volumetric sky rendering begins.
Volumetric Sky Density	Master density of the atmospheric layer.

Where to next

• Exterior lighting: sun shafts and sky-light scattering live there but require this category’s volumetric fog toggle
• Interior lighting: per-environment fog overrides for indoor spaces
• Performance tuning: volumetric fog is one of the heavier passes