Only Visible When Looked At

So basically I’m trying to build a top down 2d multiplayer game and I want the mechanics of seeing things to be like Dark Wood. Where you can see the world around you at all times, but certain things, creatures and items aren’t visible until you have it within your vision cone or flashlight if the lights are off. I imagine it has something to do with culling but i haven’t a clue where to start with it.
Also I’m having trouble with the flashlight tracking the mouse and rotating to face it without rotating the other players flashlights as well.

I want people to be able to sneak up behind others and not be visibly seen unless they turn around to look, but they can see the room they are in. Also I’m going to have to try and figure out about how people can hide behind walls and not be seen as well. like if you were to turn around they could be in the same room but you not see them as long as they are behind something big enough that would hide them like a pillar.

Here’s the coding for the flashlight tracking the mouse.

Try changeing the Bounds to something higher than 1 inside your skeletal mesh Component (of that thats gets invisible before looking at it), or adjust the Physics asset so the capsules are bigger.