allows rendering a simple refractive material meant to be used in scenes using the Toon shader. It helps preserve the outlines and and particular shading of such surfaces when seen through a refraction. For this reason, it also has no roughness
parameter, meaning the refraction is never blurred.
Sets the color of the refraction. This will affect the apparent color of surfaces seen through the material, as well as the apparent color of their outlines.
Sets the index of refraction. A higher index will result in a more significant deviation of light passing through the material.