Enlighten UE4 3.10 Release Notes

Changes in 3.10.R (UE4.24.0)

Out-of-core precompute: faster unattended build for a massive world.

Significantly reduces the system memory required when running the Enlighten Precompute commandlet for a massive world.
If your world is extremely large, uncheck World Settings > Share Lightmaps Across Levels to enable out-of-core precompute.
Out-of-core is disabled by default because it is not compatible with Detail meshes that share a lightmap from a different streaming level.

Limit the distance that Enlighten radiosity bounce and occlusion are computed, to speed up the Enlighten precompute in a massive world.

In a massive world with World Composition enabled, the streaming distance of each tile is used to automatically limit the Enlighten bounce distance.
Use World Settings > Enlighten Bounce Distance to further limit the Enlighten bounce distance. This is particularly useful for massive worlds that don't use World Composition.
In a massive world, this eliminates extreme cases where excessive memory usage could cause the Enlighten precompute to allocate all available memory and either fail or take a very long time.

Real time indirect lighting for volumetric fog.

To produce good results with real-world sunlight intensity values, Enlighten lightmaps now use a floating point pixel format for irradiance on D3D11, D3D12, PS4, Xbox One and Switch.
New example levels in the Enlighten Samples project: DynamicAlbedo and DynamicEmissive. These levels show how to control and animate the Enlighten emissive and albedo colours using a blueprint.
Reflections from Reflection Capture actors with Use Enlighten enabled now match more accurately the brightness of static reflections in a world with a bright sky.
In a massive world, use Project Settings > Enlighten > Probe Atlas Size to increase the maximum number of probes allowed by Enlighten per pixel probe sampling. Larger values increase the runtime memory required.
Landscape lightmap pixel size now matches more accurately the Output Pixel Size of the chosen Enlighten Quality. This may result in minor changes to the indirect lighting for Landscape in existing levels.
Removed rarely used Enlighten Lightmap LOD option.

Prevent artifacts in Enlighten lightmap lighting due to negative lighting values when the surface normal is zero.
Increased maximum pixel size for the Enlighten chart preview in the Static Mesh Editor to enable accurate preview of charts for meshes with Background quality.

Fixed Enlighten indirect lighting artifacts when Landscape Visibility divides a Landscape component into two pieces.
Fixed a crash after running the Enlighten precompute for a level with a duplicated Blueprint containing an InstancedStaticMesh component.
Fixed an intermittent crash when all remaining instances of a Foliage type are deleted.
Fixed some seams in Enlighten per pixel probe lighting that occur only in specific locations in the world.
Fixed missing Enlighten per pixel probe lighting in some areas close to walls.
Fixed artifacts in Enlighten per pixel probe lighting on a surface aligned exactly with the plane at Z=0.
Fixed incorrect Enlighten bounced light colour for an Instanced Static Mesh actor with multiple instances of different size.
Fixed incorrect Enlighten bounced light colour for meshes with Contribute Probe lighting mode that contain triangles larger than the Cluster Size.
Fixed missing Enlighten lighting for Landscape with a tessellation material.