Difference between Input>fresnel and Input>Layerweight>Fresnel

The function of these two fresnels are quite different. But I can’t make out what really it is. Please help.

One is measured in Index of Refraction, the other is measured in a normalized value between zero and one.

How is IOR used here? What is meant by “normalized”? Thanx for the quick reply.

The formula inside the LayerWeight is: IOR=1/(1-BlendValue)
With this we get:
blendValue = 0 >> IOR = 1/(1-0) = 1
blendValue = 0.1 >> IOR = 1/(1-0.1) = 1.1(1)
blendValue = 0.5 >> IOR = 1/(1-0.5) = 2

blendValue = 0.9 >> IOR = 1/(1-0.9) = 10
etc.

ps.: To avoid division by zero when the blend value is 1 (1-1=0), the node will clamp the blend value to 0.99999

Thanx for the formula. But another question, why to use layer weight node if we can input the IOR value directly in the Fresnel node. Hope to hear soon.

It’s just an alternative. Some people may prefer to use LayerWeight instead of a precise IOR from fresnel, or even just to have the value coming from a texture file without any math nodes in the middle.

Thanx. That is exactly what I wanted to know.