Reflection probe usage
What is a probe
A Reflection Probe captures its surroundings whereas a Planar Reflection Probe only captures one direction.
For more information on probes and how they work, see Reflection Probes.
Controlling the influence of a probe
The influence of a probe determines which pixels it affects and by how much.
There are 3 tools to control the influence on a pixel:
- Influence volume: The probe affects any pixel inside this volume.
- Blend distance: The probe affects pixels near the border of the Influence volume less.
- Blend normal distance: The probe doesn't affect pixels near the border with an invalid normal.
Use this volume to include or exclude pixels from the probe's influence.
Note: When a pixel is inside an influence volume, the probe still processes it even if the specular value the probe provides isn't significant. This is important to handle the performance of probes.
Unity linearly weights the specular lighting value the probe provides between the influence volume and the blend volume. Use blending to create smooth transitions at the border of the probe's influence, or when probes overlap.
Blend normal influence
Sometimes, a probe can influence a pixel that isn't consistent with the scene layout.
For example, when a light ray can't reach a pixel due to occlusion, but the pixel is inside the influence volume.
You can set a blend normal distance similarly to a blend distance. The probe doesn't influence pixels that are inside the influence volume, but outside of the blend normal distance, if their normal points away from the probe.