How does ROBLOXs anti-'view through walls' work?

Hey, So ya know how when you move your camera and theres a part in the way, it zooms in so the part is out of the FOV.

I'm making my own camera controls, it's basically a fixed camera looking from the top. Imagine you have a headband with a pole and a lateral stick and on the end theres a camera: thats what im doing.

In numbers, the camera is set to like your characters head's position+Vector3.new(0,25,20)

Id like to make it so that when you close to a wall and the position in which the camera is supposed to be is on the other side or inside the wall then the position is in the intersection of the line connecting your head and the normal pos with the wall.

I tried raycasting but the ray is colliding with itself, and I tried using Findpartonraywithignorelist but it still errors for no reason.

Any other way I could do that? As stated in the question I'd like to know how ROBLOX does it. Thanks