In addition to Fresnel, this group has enhancements for roughness and color.
I developed a way to take roughness into account. It mixes two Fresnel nodes.
An RGB Curves node remaps roughness values to precisely control reflectance.
Roughness values are darkened at grazing angles to enhance reflectivity.
This addresses the issue of color being too dark at grazing angles.
The first render was made with this group.
For comparison, the second render was made with the CynicatPro Fresnel.
Roughness is squared in the group. There are two roughness outputs.
One is for 2.79, and the other is for 2.8. The 2.8 output reduces the power.
A separate “Grazing Reflectivity” group is included to use with the Principled shader.
Enhanced_Fresnel.blend (89.4 KB)