reflective materials - fresnel IOR

V-Ray for Rhino V-Ray for Rhino :: General
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Hi !

im a little bit confused by the reflection layer settings:

what is the fresnel color for, and what the fresnel IOR for ?

i mean fresnel color is about the reflection linked to the angle of the camera … but why that IOR ? what does this do pariculary ?

same questions for the refraction color / refl. IOR in the fresnel(reflection layer) rollout … ???

thank you very much

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Re: reflective materials - fresnel IOR

The colors used in a fresnel map are used to set the minimum and maximum values of that map. The IOR will change how the transition between the two is made. IOR is a physically based value that you can use to simulate certain types of materials. Basically a higher IOR will make things more and more reflective.

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Re: reflective materials - fresnel IOR

sorry i dont understand…

so what does the min max values of the fresnel map say ?

Fresnel map has to color switches :

Fresnel color and refract color. And both have IOR switches.

So does Refract color gives me the reflection intesity if camera looks straight to surface and fresnel color if the angle steeper/ lower ?

excuse my english

4

Re: reflective materials - fresnel IOR

It says what the minimum and maximum reflection the Fresnel map will create. In V-Ray a number of parameters are inputted through grayscale colors…black would equal zero and white would equal 1 or 100 depending on how you’re thinking about it. So the colors would be how you manipulate the minimum and maximum values…the fresnel color will set the maximum reflection and refract color will set the minimum reflection value.

Both IOR values need to be the same.