I need help How I make shading for my GMC map?

How do I make shading

You could add a barrier thats transperent

Try barrierers.

but it would get darker out not darker in

just use layers for that

… That still would not work

Other GimGuy here, I think if you duplicate the prop and place it slightly to the bottom left of the prop it looks like shading.
Or use:
How to make in-game shadows without camera views! (Difficulty: :orange_square:)
Sorry nevermind that doesn’t work

wdym it does not work