Directonal Light

I have a directonal light in a level, and a house made of box meshes w/ colliders. the light is lighting the inner wall of the house. How is this possible? Is it the lights property or is it leaking?

Lighting is always calculated per triangle. You need Unity pro to enable any kind of shadows. If you have pro directional lights should always work. Point and spot lights will only cast shadows when you use “Deferred Lighting”. Edit–>Project Settings–>Player–>Other settings

If you don’t have pro there’s not much you can do. If it’s a stationary light you can put objects that should not receive light from a certain light on a seperate layer and exclude that layer in the light’s cullingmask.