Unlike the regular Fresnel expression node, the Fresnel function allows you to designate your own set of vectors used to calculate the equation, as well as make other adjustments to the blend.
Normal Vector (Vector3)
The first vector used in the Fresnel operation. Typically, this is the surface normal.
Camera Vector (Vector3)
The vector of the camera's direction.
Invert Fresnel (StaticBool)
This inverts the operation, reversing the way normals are calculated to yield results.
This value controls how quickly color falls off between the core and the edges.
Use Cheap Contrast (StaticBool)
This activates an internal CheapContrast function to boost the contrast of the Fresnel's result.
Cheap contrast dark (Scalar)
When using cheap contrast, this controls how much the dark value shows in the result. Has no effect when not using cheap contrast.
Cheap contrast bright (Scalar)
When using cheap contrast, this controls how much the bright value shows in the result. Has no effect when not using cheap contrast.