Unity 4.x Stencil Buffer tutorial...?

Hey there,

I am trying to achieve a game like Antichamber (http://www.antichamber-game.com/)

Mainly what I need is the portals like in Antichamber, means different rooms from different perspectives. Kind of like here: https://www.youtube.com/watch?v=5DKIP9N-OB4

I'm sure some of you have played Antichamber, it's really hard to explain to non-antichamber-players what I am trying to achieve here.

All I need is some kind of tutorial on stencil buffers - I can't find anything! I googled for hours and did not find a single thing that helped me understand how to use them. I mean, they are in Unity, people are doing stuff with them, but how?

Perhaps somebody who understands and uses them could make a detailed tutorial or something like that on them? Many thanks!

Sincerely, aleichert