Indirect Lighting Intensity
Where: select a light and search Indirect Lighting Intensity in its Details panel. This page covers the light's own property, not the similarly named Post Process Volume setting.
Direct light travels from a light source to a surface. Indirect light reaches a surface after interacting with the scene, such as sunlight bouncing from a bright floor onto a ceiling. Indirect Lighting Intensity lets you change the light's indirect contribution separately from its main intensity. Epic describes 0 as disabling that light's GI contribution in the light component reference.
Values
| Value | Intended effect |
|---|---|
| 0 | Remove this light's indirect contribution, not the light itself. |
| 0.5 | Reduce its indirect contribution. |
| 1 | Keep its normal indirect strength. |
| 2 | Increase its indirect contribution without doubling its main intensity. |
This is a per-light control. Other lights and emissive surfaces can still illuminate the room when one light's indirect contribution is reduced to 0.
How it fits Spectral
Spectral reads this property from scene lights, including the Sky Light, and passes it into its bake light parameters. Treat it as a source-light adjustment made before baking, not a live replacement for the lighting already stored in lightmaps or probes.
For example, if a sunlit floor is correctly exposed but its bounced light makes the ceiling too bright, reduce the sun's Indirect Lighting Intensity and rebake. If the sunlit floor itself is too bright, adjust the main light intensity or exposure instead.
Probe values combine lighting from the scene. Once baked, changing one light's intensity is not a way to isolate and rescale only that light inside the existing field. Also distinguish this control from Indirect Lighting Contrast in Baker quality, which shapes the probe bake rather than setting one source light's intensity.
BakerA Stationary light's live direct lighting can change while its old indirect lighting remains baked. Rebuild before judging whether the complete lighting setup matches your new values.
When to rebake
Rebake affected lighting after changing this value. Use small comparisons with other light sources held constant. Very high values can wash out contact and color balance; check material colors and the actual light placement before using this as a general brightness fix.