We have an indoor level with big ground plane and some number of (spot and point) lights there!
Some of the lights are stationary and do not overlap each other.
The problem is, after baking light “some” of our lights did not light the surface at all.
Lightmap textures looks like it calculates correctly, but surface is completely black. If we changing lights somehow, lamps that not work can be changed randomly.
If i uncheck Cast Shadows property in light then it renders correctly, but i need shadows.
Also looks like replacing our surface geometry with several smaller pieces fix lights issue, but is there any limit on square we want to know it.
This is the engine culling lights that are at a small enough screen radius to save performance.
This setting can be changed in by going to the project settings > Rendering > Min Screen Radius for Lights. The default value is 0.03. You can try a smaller value to get the distance you want, however, this can come performance cost since the lights will no longer be culled and continually rendered.
I hope this helps.