I have a material with paint and some metallic paint details too. So I have a metallic map for that with black and white.
The result looks nice but I would like to be able to control the IoR with a map, to have a much higher one for the metallic details.
In Vray (using the Spec/Gloss workflow) you can add an IoR map and this gives me the wanted result. With Metal/Rough in Blender I can’t find how to plug it in, or at least how to control the Fresnel IoR manually… Because the IoR field seems to be only for glass / refractive materials.
Is this a limitation of the Metallic workflow? Or maybe a limitation of Cycles itself? Or me being blind?
Thanks
The specular slider is for this:
It gives you some control. Oviously not as much as a curve which is often used in the specular/glossy workflow but most of the time it is enough.
Here you can see the conversation from specular to IOR which works under the hood inside the shader.
https://docs.blender.org/manual/en/latest/render/shader_nodes/shader/principled.html