How do I transfer the image a camera takes in to a box or plane?/create a portal

I want it so that when I am looking at the box/plane, that I see what the camera sees far away. Kind of like a security camera monitor, but more like that popular game where you shoot portals around and can go from one to the other.

My idea is that since we cannot rotate the terrain (I really wish we could!) that if I set up a plane above the Terrain1 which shows an image of Terrain2 then I don’t need to rotate terrain because this is sort of a cheat way to do it. know what I mean?

basically the top plane projects the image of the Terrain2 downward at Terrain1 giving the illusion of a rotated terrain. It would also be great if this “plane” could have a way to move through it, like a portal, but I will figure that part out if needed it shouldn’t be too difficult (then again I am a newbie)

What I need help with is transferring the image the camera sees onto the plane.

Any help on this would be wonderful!

also if someone can tell me what “Karma” is I don’t understand and I seem to owe some?

I think you are looking for Render textures. These however are a Pro feature.