Volumetric Scattering Intensity
Where: select a light and search Volumetric Scattering Intensity in Details.
Volumetric scattering is light made visible by fog. This setting scales how strongly a light contributes to supported volumetric fog rendering without changing its normal illumination of solid surfaces. A spotlight can therefore light the floor strongly but have a subtle visible beam, or the reverse. See Epic's Volumetric Fog reference.
Values
- 0: removes that light's live volumetric scattering contribution.
- 1: keeps the normal contribution.
- Between 0 and 1: reduces it.
- Above 1: makes it stronger.
The light's color and intensity still matter. This multiplier does not create fog density, and it cannot reveal a beam in empty air. Set up the fog first, then balance the light.
How it fits Spectral
Spectral supports probe lighting in both Spectral Fog Volume and Exponential Height Fog with Volumetric Fog enabled on the supported rendering paths.
Spectral Fog VolumeThere are two distinct sources to keep track of:
| Source | Control to inspect |
|---|---|
| A light's live contribution to the fog grid | That light's Volumetric Scattering Intensity. |
| Lighting already recorded in the probe field | The direct, indirect, and ambient probe-fog controls in Features > Fog. |
Turning a light's Volumetric Scattering Intensity to 0 does not erase its old contribution from baked probe data. If fog remains bright, check the probe contribution and other lights before assuming the control is broken. The native Static Lighting Scattering Intensity on Exponential Height Fog is another separate setting, not this per-light multiplier.
Example: a flashlight and a bright room
Reduce a flashlight's scattering if its beam overwhelms the view while keeping its surface intensity unchanged. For a room whose fog is too bright everywhere, inspect density and the probe-fog lighting strengths instead of reducing every light indiscriminately.
Volumetric fog uses temporal history. Fast-moving or flashing lights can leave visible trails. Reducing their scattering can help; also review fog temporal quality controls. Raising scattering usually makes those artifacts more obvious.
When to rebake
Changing a live light's scattering multiplier does not require rebaking. Changing the lighting recorded in probes does. Static baked lighting cannot be independently animated through this runtime control.