Ray Tracing technique was implemented back in 1980 when an American electrical engineer J. Turner Whitted described it as a novel method to compute 2D images of 3D objects. In the paper “An improved illumination model for shaded display”, published in Communications of the ACM magazine, Whitted explained the concept of ray-tracing along with some other things like anti-aliasing that we still use up to this day. For those looking for a quick glance, here