I have noticed that in HDRP pipeline (only one I have tried) that when I have either a Physically Based Sky or a HDRI sky and create a fully enclosed / sealed (hollow) black box, the objects inside the box whether static or not have a sort of “Ambient” lighting applied to them after baking. I have used 6 scaled cubes to create the sides of the sealed box.
I have tried both baked indirect and shadow mask baking and both produce the same result and it is almost like the baking is allowing “some” ambient light from the sky to pass into the box interior.
I have completely disabled the sky (each HDRI and Physically Based) as tests and just left the directional light and when baking again the interior goes pitch black as expected so I am sure it has to do with the way baking happens with a sky.
Is this intended or is there something I might be missing with the baked lighting with HDRP.
Essentially for what I am producing I would like to have the exterior nicely lit with the sky and the inside of the box not affected by the sky.
Thanks in advance for any advice.