Fresnel node


(Kumaran sip) #1

Do i need fresnel node for principle shader???


(cgCody) #2

No. Fresnel is built into the principled BSDF. The specular slider controls it’s effect.


(Kumaran sip) #3

Thankyou cody.


(cgCody) #4

Glad to help.

By the way, if you prefer working with physical IOR values in the specular slider, there’s a formula in the Blender manual:
https://docs.blender.org/manual/en/latest/render/cycles/nodes/types/shaders/principled.html
It’s the first hint in green. The default value is fine in most cases, but it’s there if you like to get technical.


(CarlG) #5

You may want to use it if you mix the principled with a manual glossy (topcoat) shader, as it’s builtin topcoat is (was?) buggy wrt topcoat roughness in that it can’t be properly texture mapped (it stays at zero until a certain threshold is reached creating a sudden change in roughness).

If you’re mixing with anything else, you probably should use a different way of mixing, as fresnel is only for splitting “what goes into the object” and “what is bounced off the object”.