Offset raycaster to the direction of the camera?

Hi guys, at this point I am pretty much hopeless with creating a flawless collision detection system because I am struggling hardly with the translations and others and I figured out I would ask one more time over here.

So, lets assume I have my camera, in order to check if anything is in its way, I want to create a raycaster at the y of camera and push it by 1 to where the camera is actually looking - only in the x, z coords, otherwise it would alter the y coord, which would break it, you know the drill. It sounds simple and maybe it even is but with my knowledge of Three it seems like an impossible feat. I hope someone here has encountered similar issue and could help, thanks for any responses.