Mass Effect style laser-scaner

In the ship there is a certain area which you have to walk past - you have to stop for a moment and a laser net scans your body. I was interested if the same could be achieved, but with the laser net invisible and, at the points of contact, a sort of light ring would be drawn around the player. I'm using c# in case of actual code appearing in the answers, but I wonder about the general technique. Thank you in advance.