Exclude objects from lights

Is there a way, that I can exclude specific objects from lights (I know about layers, but for my problem it will not work).

I want to make a game, which is tile based. A user can define with an editor, different rooms, and doors on this tile based map. Afterwards he can add lights (torches) at the wall.

This is all runtime, so I cannot use baked lights.

I want to create for each torch at the wall a point light, with some range. This should light into the room and against the wall, but because of the light is close to the wall, this means if on the other side of the wall is also a room, then this floor will be lit too.

I could solve this with casting shadows by the point light, but this slows down the performance.

My plan was to just ignore all objects lit, which are on the opposite side of the wall (like a cutting plane).

Is this possible with unity?

A quick Google search leads to the Unity documentation page for Light. The “Culling Mask” property sounds like it could meet your needs.