Override or combine rendering layer masks in a local volume to handle light leaks in cases such as doorways or shared walls.
A probe can belong to one or more rendering layers. When Unity bakes lighting, it uses ray tests and occlusion analysis to evaluate the visibility of geometry tagged with rendering layers. Unity then assigns probes to the appropriate layers.
During baking, probes cast rays that can hit multiple rendering layers. Unity assigns each probe a single mask from the four defined in the Lighting window. Unity selects the mask that best matches the rendering layers most frequently hit by its rays. You can override this automatic assignment with a Probe Adjustment Volume.
To change or combine rendering layer masks in a bounded area:
Create a probe adjustment volume in the scene.
When multiple adjustment volumes overlap, smaller volumes take precedence.
In the probe adjustment volume Inspector, set Mode to Override Rendering Layer Mask.
In the Operation tab, select one of the following options:
Select Override to replace the probe’s existing rendering layer masks in the volume with the selected mask. Use this for strict separation between spaces.
Select Add to combine the selected mask with the probe’s existing masks. Use this for a transitional zone between spaces.
Select Remove to subtract the selected mask from the probe’s existing masks. Use this to exclude a boundary region without fully redefining the area.
In the Rendering Layer Mask dropdown, select the rendering layer mask to apply.
Do one of the following:
After you preview or bake, Unity updates affected probes and applies the mask changes.
Note: If no probes are in the same layer as a given pixel, all probes have the same priority, and Unity samples baked probes as if you deactivated the rendering layer feature. The Quality leak reduction mode ensures Unity samples only valid probes.