which if I'm not mistaken is the same as: std::hermite(3, x)
I know when I added gravity model stuff I wanted to used std::legendre, but it ended up not being exactly the function I needed. Not sure why here though. maybe it's faster, but I doubt it.
Reading your post, now I can't make sense of mine. I think it's trying to be the probabilistic Hermite function, whereas std::hermite would be the "Physicist Hermite". But it also still isn't quite the right equation. I don't understand what it's doing in the graphics client, some sort of lighting distribution function.
I was thinking it could be replaced with the library function, but I guess I will leave it alone for now. At least until @jarmonik chimes in to clarify.