Custom Beast Settings

If you need a different baking setup than the one Unity is using by default, you can specify it by using custom Beast settings.

Beast reads bake settings defined in XML format. Normally Unity generates the XML file based on the configuration you have chosen in Bake pane of the Lightmap Editor window and a number of other internal settings. You can override those settings by specifying your own settings in Beast’s XML format.

To have Unity automatically generate the XML file for you, click the tab menu in the upper-right corner of the Lightmap Editor window and select Generate Beast settings file. You will notice that the BeastSettings.xml file appeared in the project next to your lightmaps and that the Lightmap Editor informs you, that your XML settings will override Unity’s settings during the next bake. Click the open button to edit your custom settings.

A sample Beast configuration file is given below:-

<?xml version="1.0" encoding="ISO-8859-1"?>
<ILConfig>
  <AASettings>
    <samplingMode>Adaptive</samplingMode>
    <clamp>false</clamp>
    <contrast>0.1</contrast>
    <diagnose>false</diagnose>
    <minSampleRate>0</minSampleRate>
    <maxSampleRate>2</maxSampleRate>
    <filter>Gauss</filter>
    <filterSize>
      <x>2.2</x>
      <y>2.2</y>
    </filterSize>
  </AASettings>
  <RenderSettings>
    <bias>0</bias>
    <maxShadowRays>10000</maxShadowRays>
    <maxRayDepth>6</maxRayDepth>
  </RenderSettings>
  <EnvironmentSettings>
    <giEnvironment>SkyLight</giEnvironment>
    <skyLightColor>
      <r>0.86</r>
      <g>0.93</g>
      <b>1</b>
      <a>1</a>
    </skyLightColor>
    <giEnvironmentIntensity>0</giEnvironmentIntensity>
  </EnvironmentSettings>
  <FrameSettings>
    <inputGamma>1</inputGamma>
  </FrameSettings>
  <GISettings>
    <enableGI>true</enableGI>
    <fgPreview>false</fgPreview>
    <fgRays>1000</fgRays>
    <fgContrastThreshold>0.05</fgContrastThreshold>
    <fgGradientThreshold>0</fgGradientThreshold>
    <fgCheckVisibility>true</fgCheckVisibility>
    <fgInterpolationPoints>15</fgInterpolationPoints>
    <fgDepth>1</fgDepth>
    <primaryIntegrator>FinalGather</primaryIntegrator>
    <primaryIntensity>1</primaryIntensity>
    <primarySaturation>1</primarySaturation>
    <secondaryIntegrator>None</secondaryIntegrator>
    <secondaryIntensity>1</secondaryIntensity>
    <secondarySaturation>1</secondarySaturation>
    <fgAOInfluence>0</fgAOInfluence>
    <fgAOMaxDistance>0.223798</fgAOMaxDistance>
    <fgAOContrast>1</fgAOContrast>
    <fgAOScale>2.0525</fgAOScale>
  </GISettings>
  <SurfaceTransferSettings>
    <frontRange>0.0</frontRange>
    <frontBias>0.0</frontBias>
    <backRange>2.0</backRange>
    <backBias>-1.0</backBias>
    <selectionMode>Normal</selectionMode>
  </SurfaceTransferSettings>
  <TextureBakeSettings>
    <bgColor>
      <r>1</r>
      <g>1</g>
      <b>1</b>
      <a>1</a>
    </bgColor>
    <bilinearFilter>true</bilinearFilter>
    <conservativeRasterization>true</conservativeRasterization>
    <edgeDilation>3</edgeDilation>
  </TextureBakeSettings>
</ILConfig>

The toplevel XML elements are described in the sections below along with their subelements.

Adaptive Sampling (<AASettings> element)

Beast uses an adaptive sampling scheme when sampling light maps. The light must differ more than a user set contrast threshold for Beast to place additional samples in an area. The sample area is defined by a Min and Max sample rate. The user sets the rate in the –4..4 range which means that Beast samples from 1/256 sample per pixel to 256 samples per pixel (the formula is: 4 to the power of samplerate). It is recommended to use at least one sample per pixel for production use (Min sample rate = 0). Undersampling is most useful when doing camera renders or baking textures with big UV-patches. When Beast has taken all necessary samples for an area, the final pixel value is weighed together using a filter. The look the filter produces is dependent on the filter type used and the size of the filter kernel. The available filters are:

• Box: Each sample is treated as equally important. The fastest filter to execute but it gives blurry results.
• Triangle: The filter kernel is a tent which means that distant samples are consideredless important.
• Gauss: Uses the Gauss function as filter kernel. This gives the best results (removes noise, preserves details).

There are more filters available, but these three are the most useful. The kernel (filter) size is given in pixels in the range 1..3. Beast actually uses all sub pixels when filtering, which yields better results than doing it afterwards in Photoshop.

Texture Bake (<TextureBakeSettings> element)

These settings help getting rid of any artifacts that are purely related to how lightmaps are rasterized and read from a texture.

Environment (<EnvironmentSettings> element)

The environment settings in Beast control what happens if a ray misses all geometry in the scene. The environment can either be a constant color or an HDR image in lat-long format for Image Based Lighting (IBL). Note that environments should only be used for effects that can be considered to be infinitely far away, meaning that only the directional component matters.

Defining an environment is usually a very good way to get very pleasing outdoor illumination results, but might also increase bake times.

Render Settings/Shadows (<RenderSettings> element)

Settings for ray-traced shadows.

Global Illumination (<GISettings> element)

The Global Illumination system allows you to use two separate algorithms to calculate indirect lighting. You can for instance calculate multiple levels of light bounces with a fast algorithm like the Path Tracer, and still calculate the final bounce with Final Gather to get a fast high-quality global illumination render. Both subsystems have individual control of Intensity and Saturation to boost the effects if necessary.

It’s recommended to use FinalGather as the primary integrator and either None or PathTracer as the secondary integrator. Unity uses the first option (so final gather only) as the default, since it produces the best quality renders in most cases. Path Tracer should be used if many indirect bounces are needed and Final Gather-only solution with acceptable quality would take to much time to render.

Final Gather

The settings below control the quality or correctness of the Final Gather solution. The normal usage scenario is this:

1. For each baking set up Contrast Threshold and Number of Rays may be adjusted. There are no perfect settings for these since they depend on the complexity of the geometry and light setup.
2. Check Visibility and Light Leakage reduction are expensive operations and should only be used to remedy actual light leakage problems. These settings will only help if the light leakage is caused by the Global Illumination calculations. A very common light leakage situation occurs with a wall as a single plane with no thickness. The light leaking through in that situation does not come from GI.
3. Gradient threshold should only be changed if there are white halos around corners.

Steps 2 and 3 should not need much tweaking in most scenes.

Path Tracer

Use path tracing to get fast multi bounce global illumination. It should not be used as primary integrator for baking since the results are quite noisy which does not look good in light maps. It can be used as primary integrator to adjust the settings, to make sure the cache spacing and accuracy is good. The intended usage is to have it set as secondary integrator and have single bounce final gather as primary integrator. Accuracy and Point Size can be adjusted to make sure that the cache is sufficiently fine grained.

Frame Settings (<FrameSettings> element)

Allow to control the amount of threads Beast uses and also the gamma correction of the input and output.

Surface Transfer (<SurfaceTransferSettings> element)

SurfaceTransferSettings are used to allow for transferring the lighting from LOD0 (the level of detail that is shown when the camera is close to an object) to LOD’s with lower fidelity. Keep the settings at their defaults.