material properties

[Guest]

Is there any relation to physical characteristics of a material and the rgb values used within Vray materials for reflection and refraction?

For example according to this table http://vrayc4d.com/manuals/glossary/ior plastic has an IOR of 1.46. But how do you work out the rgb value? i.e is it 80% black with an IOR of 1.46?

I understand that there are many types of plastic etc but is there no common look up table for most materials? Or is it just pure guess work? If it looks right then its ok?

Does gamma 2.2/ linear workflow effect these values?

I also came across this:

Material: Pure aluminum /polished Reflectance values: 65 - 75 %
Material: Matte aluminum Reflectance values: 55 - 75 %
Material: Steel Reflectance values: 25 - 30 %
Material: INOX Reflectance values: 80 - 90 %
Material: High polished copper Reflectance values: 60 - 70 %
Material: Latón muy pulido Reflectance values: 70 - 75 %
Material: Light oak /polished Reflectance values: 25 - 35 %
Material: Dark oak /polished Reflectance values: 10 - 15 %
Material: White paper Reflectance values: 70 - 80 %
Material: Granite Reflectance values: 20 - 25 %
Material: Polished marble Reflectance values: 30 - 70 %
Material: Light stucco Reflectance values: 40 - 45 %
Material: Dark stucco Reflectance values: 15 - 25 %
Material: Concrete Reflectance values: 20 - 30 %
Material: Bricks red/new Reflectance values: 10 - 15 %
Material: Glass Reflectance values: 5 - 10 %
Material: Silver mirror Reflectance values: 80 - 88 %
Material: High polished mirror Reflectance values: 92 - 95 %
Material: White tiles Reflectance values: 75 - 80 %
Material: White enamel Reflectance values: 65 - 75 %
Material: White lacquer Reflectance values: 80 - 85 %

[Guest]

I also came across this post http://robertokoci.com/advanced-vray-materials/ but they seem to be picking out RGB values with little to no explanation.

[Guest]

Can anyone answer this? I feel like I am asking to many questions around here but it is a forum after all