This is the documentation for Enlighten.
From static to dynamic lighting
- Jun Yoshino
Enlighten provides indirect lighting for Stationary lights and Movable lights. Lightmass provides lighting for lighting for Stationary lights (as shadow maps) and Static lights.
To use Lightmass lighting, Enlighten lighting must be disabled in Project Settings.
Before you set up your existing level to use dynamic Enlighten lighting, to ensure that there is no stale data left over from a previous Lightmass build, we recommend you remove all existing Lightmass lighting data.
Remove Lightmass lighting
To remove Lightmass lighting:
- Under Details > Transform, make sure the Mobility for each light is set to Movable.
- In World Settings > Lightmass Settings, click the reset arrow to reset all the settings to the default.
- Run Build > Build Lighting Only to rebuild the lighting.
The Lightmass build should complete quickly.
If UnrealLightmass.exe is missing, the lighting build fails and the editor reports an error. This happens if you didn't compile UnrealLightmass.exe when you installed Enlighten UE5.
Verify that your level only uses Enlighten indirect lighting
To hide and show Enlighten indirect lighting, toggle Show > Lighting Features > Enlighten Indirect Lighting.
If your level uses only Enlighten indirect lighting, you should now see only the direct lighting. To hide and show the direct lighting, toggle Show > Lighting Components > Direct Lighting.
Minimize dynamic shadow cost
Enlighten leaves the computation of direct lighting and shadows to the Unreal Engine renderer. For a Movable light, the cost of Unreal Engine dynamic shadows can be significantly higher than for static shadows.
The cost of Unreal Engine dynamic shadows varies with the configuration of meshes and lights in the level. If you find that the cost is excessive for your level, try one or more of the following approaches to reduce the cost:
- For point and spot lights that move, turn off shadows or use Shadow Map Caching (Unreal Engine documentation)
. - Movable directional lights cast shadows for the whole level and therefore incur the most cost. Where possible, disable shadowcasting per actor.
- Depending on the level, general optimization techniques such as merging actors (Unreal Engine documentation) can significantly reduce the cost of shadows.
Each of the above optimizations requires additional artist time to configure the level. We recommend that you apply each optimization only if you have problems with the cost of dynamic shadows.