How to hide actors behind the character?

I’m trying to figure out how to fade out any actors the begin to touch the spring arm.

So if the player walks into the room, the wall will fade out so you will be able to see all in the room.
Something else I want is for other objects on the wall were to fade out to as to provide a more consistent transition.

How could this be accomplished?

This is the article of intention which I am interested in because all of a sudden I sat down and thought that how these characters are made on a person who is an actor. I must say that I really enjoyed reading this article because it was the thing I need to know and today open review I cleared all my doubts.

All thanks to that creative author who wrote and shared this article.