Gloss value

[Siger_1]

Hi,
I use Glossmeter to measure gloss values for some materials (in Gardner scale or GU - gloss units). Angle 20, 60, 85 degrees. Is there an algorithm to convert these values to current BRDF of Corona material? Or can use as percentage?

[Siger_1]

For example how I use in V-Ray. Example: flat/matte wall paint with gloss value at angle 60 degree = 38.2 GU
To compensate normal bump +10%
Gloss map with value mean 48% gray.