The author's name is the first hint, and the lack of ray tracing the second
I choose to interpret it as: How do you know that *the author* was not named after ray-tracing?
Which is amusing :)
You missed the joke, so let me ruin it by explaining it:
What if Ray the person was named after ray-tracing by his parents?
Plot twist: Ray Tracing was the name of a person that was very important to both of them and unfortunately passed away, so they named their son Ray as a tribute.