Displaying a "camera" for a player's screen

So you have this map, ok? Think it has a screen and some cameras.
Think you press buttons to switch cameras.
Those “cameras”, I don’t know what they are in hammer, but how do I force put them on a player’s screen? Or even create a separate camera entity. (ONLY IF 100% REQUIRED)

You could use eTrigger

I don’t get it…?
Plus, I want it to happen when a player presses a key and to be togglable, NOT when he’s in an area. And I thought it should work like a screen overlay, not like uh… whatever that is.

render.RenderView()

Like the rp_evilmelon mayor office?

Are the cameras themselves purely aesthetic or are they functional like the ones on cs_assault in 1.6?

The cameras on the maps are RT Cameras. Pretty much, there’s a material (that I don’t know off the top of my head) that you can use and have it draw on players screens if that’s what you’re wanting to do.