This page gives detail about the Reflect IOR Color Channel.
Overview
The Reflect IOR Render Channel returns an image with floating-point values that correspond to the Fresnel IOR (index of refraction) values of scene objects' materials. This render element is useful for baking the IOR parameter values for later loading in a real time visualization engine.
IOR values at or above 1.0 are represented as pure white. Note that it is common for IOR values to be above 1.0, which means portions of the image might appear as uniformly white when there are actually many different IOR values present.
Sampling the pixel values in the non-black areas will return the precise floating-point Fresnel IOR numbers for that portion of the object. The image at right shows an IOR value of 1.6 being sampled with the Show Pixel Information tool in the V-Ray Frame Buffer.
UI Path
||Node Editor|| > Add > Render Channels > Color Channel > Type > Reflection IOR
