Fresnel Effect Node

Description

Fresnel Effect is the effect of differing reflectance on a surface depending on viewing angle, where as you approach the grazing angle more light is reflected. This effect is often used to achieve rim lighting, common in many art styles.

The Fresnel Effect node approximates this by calculating the angle between the surface normal and the view direction. The output value is a floating-point number between 0 and 1. This value represents the viewing angle relative to the surface and the Fresnel effect that is being calculated:

0: The viewing angle is 0° from the surface normal, as if you are looking straight at the object.
1: The viewing angle is 90° from the surface normal, as if you are looking along the surface or edge of the object.

A low Fresnel value (output value of 0) means the surface appears as if viewed from the front, with minimal rim highlighting. A high Fresnel value(1) means the surface appears as if viewed from the side, with a strong rim highlight.

Ports

Name	Direction	Type	Description
Normal	Input	Vector 3	Normal direction. By default bound to World Space Normal
View Dir	Input	Vector 3	View direction. By default bound to World Space View Direction
Power	Input	Float	Exponent of the power calculation
Out	Output	Float	Output value

Generated Code Example

The following example code represents one possible outcome of this node.

void Unity_FresnelEffect_float(float3 Normal, float3 ViewDir, float Power, out float Out)
{
    Out = pow((1.0 - saturate(dot(normalize(Normal), ViewDir))), Power);
}