This is the documentation for Enlighten.
Real-world sun/sky intensity
This is an experimental option, and is currently only functional on D3D11, D3D12, PS4 and Xbox One.
In a level with a directional light with an Intensity of above 16
, or a sky light with Intensity above 1000, you may notice darker-than-expected indirect lighting with Enlighten lightmaps. This is because Enlighten lightmaps in UE4 are stored with a fixed-point HDR representation.
Real-world values for sunlight may require an intensity of around 2000
. In this scenario, Enlighten indirect lighting looks dark and flat.
To fix this, you can enable experimental floating-point HDR lightmaps, which:
- display much greater range of values while preserving precision where it's most needed
- don't require additional memory
- don't significantly affect GPU or CPU overhead
To enable the floating point pixel format for the irradiance lightmap:
In your project's DefaultEngine.ini, add the line:
 r.Enlighten.LightmapPixelFormat=1
- Restart the editor.