A room without windows is lit up

[slboi]

Hello,

so a have a room without windows, and it is strangely illuminated

The plugins

• Sun Shadows
• Voxel Global Illumination
  are turned on. I tested different options too.

I double-checked the normals of the walls. Per construction the walls overlap and the environmental light should not enter the room and therefore it should be black. I would like to add some windows later to get something like in your examples here

https://www.youtube.com/watch?v=2Ll1x61MB2M

Unfortunately, the walls are always illuminated from inside. The panda native ambient light has no effect on the scene. I set it like this

alight = AmbientLight('alight')
alight.setColor((0.0, 0.0, 0.0, 1.0))
alnp = render.attachNewNode(alight)
render.setLight(alnp)

I have no clue what I am doing wrong. So my only option for now is to set the day time to "night" and model the light from windows with "SpotLights", which I think is not right.