Realtime GI without directional light

Unity Engine
1

I’m learning how to work with GI, and trying to get good looking lighting in my indoor environments. Please correct me if I’m wrong, but I’ve noticed that realtime GI only works in the following setup - directional light + skybox. If I understand the operating principle of GI correctly, the only two sources of indirect light in the entire setup are directional lights and the skybox. All the tutorials on using realtime GI show a fancy indoor scene with a window through which the indirect light pours in. Remove the window and the scene falls appart.

What if the setting is an underground dungeon? There are no windows, so directional lights and skyboxes are hardly applicable in this case, and point and spot lights give the warning “realtime indirect bounce light shadowing for spot and point lights is not supported”.

So is it true that you can’t actually have indirect light in a closed indoor environment?

2

You are wrong.

The warning about the shadowing is that for spots and point lights, GI isn’t aware of direct shadows. (so you might see bounced light originate from areas that should be blocked by direct shadows). It otherwise works just fine.

You can also use emissive materials.