Enlighten lightmaps provide diffuse indirect lighting for static actors.

The image below shows how Enlighten maps lightmaps to surfaces.

Each colored area is a chart, a continuous area of the lightmap UV space. For example, the blue wall is one chart. There's usually a hard edge in the Enlighten lighting where charts meet, such as the edge between the blue and orange walls in the image above.

Enlighten lightmaps contain only low-frequency indirect lighting and require much lower resolution than traditional, baked lightmaps.

The default lightmap resolution is one pixel per meter; this is more than enough for high-quality indirect lighting. Instead of specifying a fixed-size lightmap for each mesh, you can specify the size of a lightmap pixel in world units and the UV layout automatically adjusts. The more pixels you use, the higher the Enlighten lightmap cost. You can adjust the lighting resolution to find a balance between cost and quality.