Metalness and IOR

[Ihno]

Hi,
there is this great article about how to use metalness:
https://www.chaosgroup.com/blog/understanding-metalness

I would love to know how vlado came to the numbers in the chart using the data from RefractiveIndex.info

[PIXELBOX_SRO]

the RGB values are very interesting since i have been reading everywhere for ages that the RGB value of such material as silver is meant to be black not almost white...why this change all of the sudden? Is this beacause of the metalness workflow? That woudl be odd..
Thanks for mor einput on this!
Martin

[vlado]

the RGB values are very interesting since i have been reading everywhere for ages that the RGB value of such material as silver is meant to be black not almost white...why this change all of the sudden?

This is what comes out of the data at refractiveindex.info; I suppose if the silver is oxydized with time, it might go darker.

Best regards,
Vlado

[Rens]

the RGB values are very interesting since i have been reading everywhere for ages that the RGB value of such material as silver is meant to be black not almost white...why this change all of the sudden? Is this beacause of the metalness workflow? That woudl be odd..
Thanks for mor einput on this!
Martin

Yeah the diffuse is supposed to be either black or close to it when not using the metalness option.

So what does metalness do? This is a simplified explanation:
Imagine a standard 3dsmax Falloff map, metalness basically has this as the reflection map, then it basically copies the diffuse colour to the front reflection colour and sets the side colour to white.
The diffuse colour is now set to black.
The front/side mix in this falloff map is controlled by the IOR/Fresnel.

Personally I always like a bit of diffuse mixed in as it looks more realistic unless you have a 100% perfect surface.