IOR to Specular Level (dielectric) by Jens Kafitz
IOR to Specular Level (dielectric) will convert IOR Values of dielectric materials (non-metal) to a Specular Level Value.
Specular Level Maps are popular in a game-PBR workflow and are found for example in Unreal Engine, can be output from Substance Products etc..
You can also utilize Specular Levels in the Mari UNREAL and Extension Pack UNREAL Advanced Shader (just called 'Specular')
They define the reflectance of dielectric (non-metal) materials from 0 % (0.00) to 8 % (0.08) via a remapped value of 0 to 1.
In most cases these Specular Levels are set to 0.5 which in Reflectance terms is a 0.04 surface reflectance or IOR 1.5 equaling plastic.
Some sample measured Specular Level Values can be found below (taken from UNREAL Engine Documentation)
Material Specular Level
When the Manual Input option of the node is disabled you can feed in values from other layers or nodes
that will then be converted.
When ticked, the Node will no longer act as an adjustment layer, converting values fed in from other nodes
or layers. Instead it will output the converted value from the IOR Value entered via the Slider.
The IOR Value to convert when Manual Input is enabled
Created with the Personal Edition of HelpNDoc: Create cross-platform Qt Help files