This is the documentation for Enlighten.

9. Efficient Enlighten lighting

Owned by Jun Yoshino
Aug 02, 2022
3 min read

When you use lots of lightmap pixels or probes:

  • the Enlighten precompute takes longer
  • the Enlighten data becomes larger
  • the time between each lighting update increases

Fortunately, you don't need many pixels or probes to provide high-quality indirect lighting. A relatively small number is sufficient.

The Enlighten configuration for this level strikes a balance between accuracy and cost. The Enlighten Lighting Mode, Enlighten Quality and Enlighten probe resolution keep the number of lightmap pixels and probes small, while providing believable indirect lighting.

In large levels, certain configurations can result in a very large number of lightmap pixels, which might cause the precompute to take a long time.

Radiosity contribution

The level is configured to exclude actors which don't reflect a noticeable amount of light from the Enlighten computations. For example, light reflected by small or thin objects makes very little difference to the overall lighting effect, so they're not included. This reduces the Enlighten lighting complexity.

  1. Make sure the View Mode is set to Lit.

  2. From the Show menu, select Use Defaults to show the level with the default editor visualizations.

  3. To see which actors are included in the Enlighten computations, in the View Mode menu, choose Enlighten > Radiosity Geometry.

    Enlighten > Radiosity GeometryLit

    When Radiosity Geometry is enabled, small objects, such as drainpipes, lampposts, and satellite dishes are excluded from the editor view. These are the objects excluded from the Enlighten computations.

  4. Set View Mode to Lit to show the small objects again.

  5. In the Outliner, double-click Props_LampPost01 to focus on it.

    This actor isn't included in the Enlighten computations because it wouldn't reflect much light.

  6. Change the view mode to Lighting Only.

    Notice that the lighting around the actor is still believable, even though it reflects no light.
    You can choose which actors are included in the Enlighten computations in the Details panel by changing the Enlighten Lighting Mode. This is described in the next tutorial.

  7. Choose View Mode > Enlighten > Lighting Mode.

    In this level, only actors lit with lightmaps (orange) are included in the Enlighten computations.