Unity Products:Amplify Shader Editor/Fresnel
From Amplify Creations Wiki
Fresnel Node
The Fresnel node outputs the result of a Fresnel effect. It defines how light behaves when it reaches an interface between two materials with different refractive indices, how much of it is reflected and refracted.
This node in particular deals with the reflection part and calculates the Fresnel Reflection Coefficient which is defined by the following expression ReflectionCoefficient = Bias + Scale x ( 1 + N.I )^{Power}.
Each member of the equation can be modified except the I variable which defines an Incident vector from the camera to the object and is internally calculated by the node as the inverted World View Direction vector.
Nodes used:
Float,
Texture Sample,
Fresnel,
Color,
Multiply
Node Parameter  Description  Default Value 

Normal Space  Specifies in which coordinates space the normal vector is

Tangent 
Bias  Defines the Bias variable of the Fresnel equation. Only visible if the respective input port is not connected.  0 
Scale  Defines the Scale variable of the Fresnel equation. Only visible if the respective input port is not connected.  1 
Power  Defines the Power variable of the Fresnel equation. Only visible if the respective input port is not connected.  5 
Input Port  Description  Type 

Normal  Normal vector to be used. Surface world normal will be used if left unconnected.  Float 3 
Bias  Defines the Bias variable of the Fresnel equation.  Float 
Scale  Defines the Scale variable of the Fresnel equation.  Float 
Power  Defines the Power variable of the Fresnel equation.  Float 