ImportLightProbes

ImportLightProbes

Unity version: 2020.3

This sample shows how to import externally-generated (e.g. in Blender) lightprobes in a scene in the Editor.

In its initial state, the "ImporterScene" scene has 8 light probes and no GameObjects contribute to the Global Illumination (i.e. light probes). 5 spheres were added to visualize the light probes.

probes.txt contains the light probe positions and spherical harmonics in a csv format. These coefficients were generated with the GameObjects under Environment set to "Contribute Global Illumination" and the External Bake Light enabled.

To trigger the import process first load the "ImporterScene" scene and then use the "Light Probes" menu in the editor.

• "Import light probes" imports light probe positions and SH coefficients.
• "... [n]" does step n of "Import light probes". For debugging.
• "Log light probe data" outputs to the console the current light probe data.
• "Reset light probes" reverts to the default light probe setup.
• "Clear baked data" clears the baked lighting data.

Switch between the "ImporterScene" and "EmptyScene" scenes to validate that the import worked.

Note that it's best to set the Lightmapping settings to their lowest values to make the "dummy" light baking step faster.

Caveats

• Don't import with an additive scene loaded. This is because Unity creates a "merged" LightProbes object in that case which can interfere with the light probe data's serialization to disk.
• Importing positions is straighforward through LightProbeGroup.probePositions. Serializing (i.e. saving to disk) the imported coefficients is not as direct and we need to make sure to save LightmapSettings.lightProbes.
• As this is not directly supported (at the moment) by Unity, please add some tests to validate the light probes are correctly imported and saved in your use case.

Results

Initial state:

Positions imported and "dummy" bake done with light probe preview active:

Final result with light probe preview active: