V-Ray - Using Readings From Gloss Meters


#1

I’m trying to find a way to use the data recorded from a gloss meter or spectrometer when creating materials. Our client often provides us with this data and while we can eye-ball it, it’d be helpful to have some sort of correlation.

For example, a soft-touch/rubberize surface has a gloss reading of about 5gu (gloss units), a satin finish plastic or bead blast anodized aluminum has a reading of 17gu. By eye we find this to the soft-touch to be about 0.6 reflective glossiness, satin plastic closer to 0.75, but with the different in conditions before holding a small sample chip and our shader ball that’s just a baseline guess.

I’ve looked all over for information on this and have come up empty.

Thanks


#2

Hmm, after reading up on Gloss Units a bit, it seems like to me it’s a factor of angle (incidence) just as much a reflective strength. I couldn’t find the exact equation, but that would be really helpful. I think this might be a component better addressed by the BDRF curves or Fresnel strength, as opposed to the actual glossiness setting itself?

OR if we could determine the math of the glossiness setting (which is probably in a white paper somewhere) that might help us make the conversion, but GUs are still definitely based on incident angle of the light, not just magnitude of the reflection.