Display and adjust Probe Volumes

You can use the Rendering Debugger to see how HDRP places Light Probes in a Probe Volume, then use Probe Volume settings to configure the layout.

Display Probe Volumes

To display Probe Volumes, open the Rendering Debugger.

You can display the following:

  • Enable Display Probes to display the locations of Light Probes.
  • Enable Display Bricks to display the outlines of groups of Light Probes ('bricks'). See Understand Probe Volumes for more information on bricks.
  • Enable Display Cells to display the outlines of cells, which are the units that streaming uses.
  • Enable Debug Probe Sampling to inspect details about Probe Volume sampling at a given world position.

To update the location of Light Probes, bricks, and cells automatically when you change settings, enable Realtime Update.


The Rendering Debugger with Display Probes enabled.


The Rendering Debugger with Display Bricks enabled.


The Rendering Debugger with Display Cells enabled.


The Rendering Debugger with Debug Probe Sampling enabled

Adjust

Adjust Probe Volume size

To achieve the highest quality lighting, you should enable Global in the Probe Volume Inspector, so the Probe Volume covers the entire Scene.

You can also do the following in a Probe Volume Inspector to set the size of a Probe Volume:

  • Disable Global and set the size manually.
  • Disable Global and select Fit to all Scenes, Fit to Scene or Fit to Selection. See Probe Volume Inspector properties for more information.
  • Select Override Renderer Filter, then select which layers HDRP considers when it generates Light Probe positions. For more information about Layers, see Layers and Layer Masks.

You can overlap multiple Probe Volumes in one Scene or Baking Set.

Adjust Light Probe density

If your Scene includes areas of detailed geometry, you might need to increase Light Probe density in these areas to achieve a good lighting result.

You can use the following to adjust Light Probe density across a whole Probe Volume:

  • In the Baking Set properties, set the Min Probe Spacing and Max Probe Spacing - which affects all the Scenes and Probe Volumes in the Set.
  • In a Probe Volume's Inspector, adjust the Override Probe Spacing slider - which affects only the Probe Volume, and overrides the settings set in the Baking Set.

Note: In the Inspector for a Probe Volume, the values in Override Probe Spacing can't exceed the Min Probe Spacing or the Max Probe Spacing in the Baking Set Settings.

If you increase Light Probe density, you might increase bake time and how much disk space your Probe Volumes use.

Use multiple Probe Volumes

You can use multiple Probe Volumes to control Light Probe density in more detail across a Scene or Baking Set. For example:

  1. In the Baking Set properties, set the probe spacing to between 1 meters and 27 meters.
  2. To cover empty areas, add another Probe Volume, enable Global, and override the probe spacing to between 9 meters and 27 meters.
  3. To cover a smaller high-detail area, add another Probe Volume, disable Global, set a smaller size, and override the probe spacing to between 1 meters and 9 meters.

Terrain

Because terrain is detailed but less important to you than your main scenery or characters, you can do the following:

  1. Put terrain on its own Layer.
  2. Surround the terrain with a Probe Volume.
  3. In the Inspector for the Probe Volume, enable Override Renderer Filters, then in Layer Mask select only your terrain Layer.
  4. To adjust Light Probe density to capture more or less lighting detail, enable Override Probe Spacing and adjust the slider values.

Additional resources