The origin is really unclear. It's not certain which id employee added it to Quake 3 and where they got it from. John claims it wasn't him. Gary Tarolli, one of the founders of 3dfx, claims to remember tweaking the value of the hex constant to the value known today. But he says he didn't come up with the algorithm either. Maybe somebody else at 3dfx did, maybe he got it from somewhere else.