thebookofshaders/glossary/reflect/README.md

Reflect

Calculate the reflection direction for an incident vector

Declaration

float reflect(float I, float N)  
vec2 reflect(vec2 I, vec2 N)  
vec3 reflect(vec3 I, vec3 N)  
vec4 reflect(vec4 I, vec4 N)

Parameters

I specifies the incident vector.

N specifies the normal vector.or.

Description

For a given incident vector I and surface normal N reflect returns the reflection direction calculated as I - 2.0 * dot(N, I) * N.

N should be normalized in order to achieve the desired result.

See Also

dot(), refract()