Glossy index

[pailhead]

Is there a thing like index of glossines? Something like a general guideline how glossy certain materials should be. Can this even be measured somehow in real life?

[percydaman]

i dont think it can be measured unfortunately. infinite number of variations im afraid.

[instinct]

it can be measured for one specific material. Not translating to faked speculars or glossiness tho. Called BRDF measurement and it measures a whole lot more then just glossies. But it's still pretty damn expensive and not exactly "comfortable" to use. Plus it removes quite some control.

Thorsten

[percydaman]

well the problem is the specific material. say its a piece of varnished wood. the variations possible in just the varnish, would just make it difficult to get a baseline.

[zoranm]

As Percydaman said it is almost imposible to compile usefull results because there is so many variables involved.
I had once one of these tables and found it useless: values have ranges so wide that it renders it unusable.

For example:

Limestone: 35-55%
Polished aluminium: 65-75%
Oak polished: 20-35%
Polished marble: 30-70%

Instead I use a "guess what looks good" aproach

Zoran

[pailhead]

I heard about those BRDF measurments. A friend of mine uses Inspirerer with this information to produce very accurate lighting analysis.

Although, i still wonder, why couldn't a simple test be made, just by measuring a diameter of a highlight on a sphere made out of certain materials?

[studioDIM]

because maybe it's not linear the way the specular changes given light angle and light size.
A guess, hey...

I hear even with IoRs there are issues (in maxwell) in that oftetimes complex, measured IoRs don't work as the user expects.
But it's stuff i gathered from their forums, not personal tests...

Lele