I've spent some time researching the Fresnel effect as part of learning how to make shaders and, although I got how it works and how to calculate it, I haven't been able to figure out why it works.
Why does a surface become more reflective and less transmissive as the angle of incidence increases? What causes it? And what does it have to do with refraction, why does the index of refraction affect the amount of reflection.
Not a physicist so please not too heavy with the math.
