Reflection off of curves? Check. All you need to do is calculus! ezpz

Haven't seen you in a while, Zee! How have you been. And the refraction is cool.

I got the derivative part, but once you have the angle, how do you calculate the new angle? Does it use the dot product?

I subtract the angle the light is traveling from 2 times the angle of the derived slope. Essentially what it is meant to do is flip the angle over a mid-line, it took me a while to come up with the formula.

So is: 2(Slope angle) - (Light Angle) ?

yup!

Oh Interesting Thanks!