This is the documentation for Enlighten.

Radiosity tab


The Radiosity tab allows you to experiment with the appearance of the radiosity and the trade-off between radiosity quality and performance.

Radiosity options

  • White material albedo — Substitutes texture albedo with solid white.
  • White duster albedo — Radiosity behaves as if all objects in the scene have solid white albedo.

    When selected, bounced light does not reduce intensity due to albedo. This is equivalent to a perfect surface that reflects 100% diffuse light. Enabling this mode often "blows out" the scene with excess light.

  • Disable emissive surfaces — Allows you to temporarily disable emissive surfaces to view the input from point/spot/directional lights only.

Bounce intensity

Allows you to adjust the amount of radiosity transferred in each bounce pass. Enlighten bounces are handled in a feedback loop. Enlighten computes the first bounce at full intensity, but allows you to scale how many of the subsequent bounces of the same light should be computed. The setting of this has no impact on performance or memory but allows the user to control how "ambient" the indirect lighting in Enlighten appears.

  • A value of 0 implies only the first bounce is considered — the light from all subsequent bounces is removed. This tends to give a sharper contrast to the indirect lighting and may be suitable where a large range of lighting values is desired.
  • A value of 1 implies all bounces are full computed and gives a "warm" ambience. However, for the lighting computation to remain stable some light must be lost in the scene, either through lighting escaping into space or through non-white surfaces absorbing some lighting.
  • The default value of 0.9 gives essentially the same appearance as 1 but removes some light so the lighting remains stable under most circumstances.

Skylight colour

The RGB intensity of the skylight used in the 'Irradiance + Skylight' lighting technique.

Radiosity task output scale

This is a scale factor passed to and applied inside the Enlighten radiosity solver. This slider is not intended to be an authoring control but allows you to test the impact of changing the internal scaling of lighting before conversion to integer output formats.

Radiosity shader output scale

This is a scale factor applied in the shader on the GPU to the indirect lighting results. This slider allows you to artificially boost the apparent amount of all indirect lighting in the scene without affecting the computation itself. It can be helpful if you wish to rebalance the amount of direct and indirect lighting.

For similar controls, including radiosity tone mapping, see the Post Processing tab.

Baked shader output scale

The global baked lighting output scale multiplier for shaders.

Compressed probe max value

The maximum value that can be represented with compressed probes. For more information, see Solving for probe points.

Probe volume texture spacing

Sets the spacing of probe volumes in dynamic object volume textures.

Use LRB format for irradiance rendering

Switches between FP16 and LRB format for the Enlighten irradiance output.

For more details about the LRB output format, see LRB Compressed Output Format for Irradiance.

Asynchronous GPU spotlight visibility

Calculates spotlight visibility with the GPU. When disabled, input lighting for radiosity is calculated on the CPU, and spotlight shadow casting does not occlude bounced light. When enabled, the GPU is used to compute shadows for spotlights. This can have a performance impact due to the synchronisation overhead this introduces (this overhead is possible to remove in a production engine).

GPU visibility using projected input samples

Toggles whether the visibility computation for Enlighten dusters to spot lights is performed on duster positions that have been projected onto detail meshes. Note that this is only relevant to scenes that use mesh projection.

Interpolate radiosity texture

Uncheck this box to use point sampled texture filtering when sampling from the radiosity textures during radiosity rendering.

Bounce Quality

Sets the bounce quality, a value between 0 and 1. See Bounce Resampling

Half precision input lighting

Use half precision for storing input lighting.

Compute radiosity-only cube maps

When checked, specular cube maps contain just indirect, radiosity lighting i.e. material albedo, emissive and direct lighting are omitted.

Entire probe set solver

Use the Entire Probe Set solver.

  • Solve L1 — Compute L1 spherical harmonic output
  • Solve L2 — Compute L2 spherical harmonic output

Enable normal maps with baking

  • Disabled — Do not render baked output with normal maps.
  • Using directional light maps — Use the Half-Life 2 basis for the baked output.
  • Using baked directional irradiance — Use the directional irradiance texture for the baked output.