View Full Version : reflect and refract IOR misunderstanding in vray

08 August 2012, 02:44 PM
Hello everyone!

I have a little misunderstanding issue about fresnel IOR (reflection) et the IOR (refraction). I know what they do and how to use it, this isn't the problem.

Anyways in a Viscorbel's tutoriel he gives us those numbers for the fresnel IOR:
water 1.33
plastic 1.45
glass 1.5-1.8
diamond 2.4
compound materials like wood, stone, concrete etc 3-6
metals 20-100

Up till there everything seems OK, but you gotta know something: the fresnel IOR and IOR are actually linked in V-ray (i read the manual) because this is how the materials work in real life. It means that if a material has an IOR of 3 then its fresnel IOR is 3 as well. This is why those 2 numbers are linked in the material slot by the L button.

So what's the matter? Well a bit further in the tutorial he gives a list of IOR (refraction this time), and look what we got:
Steel 2.50
Chrome Green 2.4
Chrome Red 2.42
Chrome Yellow 2.31
Chromium 2.97

How is this possible? Fresnel IOR and IOR have to have the same number, so in this case, those metals must have had an IOR more than 20 and less than 100 according to his fresnel IOR explanation .. :surprised

Can anyone help me out? This is really disturbing!
Thank you very much!
Have a nice day :)

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