[Solved] How to see other players through walls?

First off, I'm happy to see that the old way on making a question is back. Now onto the problem. I am making a horror type of game. One the players, as a monster, should be able to see through walls. I was thinking I would make a gui, that for every player in the game would create a new image label, set the image of the image label as a picture I already have and move the image label on the screen according to where the player is. I know there are calculations involved, like the position of both players, the direction the monster is facing, etc. Can someone help me on how to do these calculations. Thanks in advance!