Bright inside Room WITHOUT any light - i don't get it...

i build a room which is completely closed, no doors, no Windows.
there is NO LIGHT inside, Nothing.
but evcerything is lit.
ist like there is a bright light inside,
i dont get it… what am i doing wrong?

did u bake lights

yes, build Lights successfully. but the room is bright, and i do not have any Lights inside…

Could be auto exposure making something that is basically completely black look much brighter than it is.

Or you have a skylight that is adding ambient lighting that is not being occluded.

Or you have light leaking.

You can check creating a diffuse grey material (No reflections). Add light blockers in case of potential Light Leak.
Remove Auto Exposure.
Hope this helps

So when you say that the room is completely closed you mean the walls, floor, and roof have back faces?

A photo or even a sample file would help.

So based on the Realistic Rendering project from Unreal, I found they use another mesh to block outside light. Seems that because our wall only block the light they are facing, and they facing inside, so no outside light blocked For some reason !

Solution: Block outside light with another mesh facing outside (face normal) with black material, and If you have window, don’t put anything in that part so lights can pass.