This is the documentation for Enlighten.

8. Review the result

We've now configured the level for Enlighten. The changes you made affect the actors included in the Enlighten computations. The effect on the Enlighten lighting isn't visible until you run the Enlighten precompute.

  1. From the Build menu, select Enlighten Precompute.

    The precompute should take only a few minutes.

  2. After the precompute finishes, from the Show menu, select Use Defaults to show the level with the default editor visualizations.
  3. Press Ctrl + H to make sure no actors are hidden.
  4. In the Show menu, under Lighting Components, disable Ambient Occlusion.

    Ambient occlusion darkens areas of the image. Disabling it makes the effects of Enlighten easier to see.

  5. Select View Mode > Lighting Only to show only the lighting in the level.

  6. As in the See what Enlighten can do in Unreal tutorial, the direct lighting in the level comes from the DirectionalLight actor. Enlighten handles only the indirect lighting (the light from the sky and the reflected light visible in shadowed areas).
    In the Show menu, under Lighting Features, disable Enlighten Indirect Lighting.

    Enlighten Indirect Lighting ONEnlighten Indirect Lighting OFF

    Objects reflect light, creating realistic illumination in shadowed areas. This indirect lighting is provided by Enlighten.

    The lit areas are illuminated by the sun. Areas in shadow from the sun are completely black.

    You can enable and disable Enlighten Indirect Lighting to understand which parts of the lighting are handled by Enlighten. 
    For example, if you want to make an area brighter or darker, you can use the Enlighten Indirect Lighting to see how much of its lighting is handled by Enlighten, and make adjustments as necessary.

  7. In the Show menu, re-enable Lighting Features > Enlighten Indirect Lighting.
  8. In the Outliner, double-click the actor Props_Awning_6 to focus on it.


    The wall under the awning uses high lightmap quality, which is sufficient to capture the soft shadow under the awning.

    Enlighten > Lighting QualityLighting Only

    The chart is blue (high quality).Note the shadow under the awning.
  9. Let's look at one last example of how Enlighten lights the level. In the Outliner, double-click the actor Buildings_Wall_Tiling9 to focus on it.

  10. With the Lighting Only view mode, you might notice a seam between the wall actors. This is caused by the actors using different Enlighten quality levels. This shouldn't be a problem, since in Lit mode, the seam isn't noticeable.

    Lighting OnlyEnlighten > Lighting QualityLit

    Note visible seam in the wall.The seam is caused by the different lighting quality levels.When the level is lit, the seam isn't noticeable.
  11. In the Outliner, select the DirectionalLight actor.

  12. In the Details tab, under Transform, set the Rotation X, Y, Z values to X:0, Y:-50, Z:0.

    This rotates the DirectionalLight so that the direct light reaches the wall in the alley. Notice the reflected light has a red tint.

    Lighting OnlyUnlit + Enlighten Quality

    As the lower levels of the building use High quality, they capture light reflected from the DirectionalLight more accurately. The effect is still visible on the higher levels that use Medium quality, but the result is less accurate due to the larger lightmap pixel size.