This is a simulation of reflection and refraction from one material to another. I is the Incidence Ray, R is the Reflected Ray and T is the Refracted Ray. θ₁ and θ₂ are the angle of incidence and angle of refraction respectively. n₁ and n₂ are the refractive indexes of the two materials. The refractive index is how fast light can pass through a material. For example, the refractive index of a vacuum is 1, water is 1.33, and glass is 1.5
