Light probes — Unity

In a game there are static, dynamic objects without light source.

A static object can have a light emission (it must be static, and its light must be baked), and when a dynamic object is nearby, the light data from the static object can be read and get by the dynamic object.

How does the baked data get on the dynamic object? Using light groups or light probes.

A light probe is a coordination of lights that will pick up baked data and rely it to dynamic objects.

To modify light probes positions, we use the Edit Light Probes option

When that option is on, it enables the options below it

So, you can Add more probes to the group, duplicate, etc.

The objective is to place the probes everywhere the baked data can influence a dynamic object.

It could be some like this

This is the scene lighting (it has only the directional light)

The light probes involved to make it work

All these light probes are sharing lighting data, so when a dynamic object passes through them they will be illuminated with that baked data.

It generates performance improvements by avoiding the use of several lights that can make a reduced performance impact, specially for mobile devices