Roughness Curiosity

[peterguthrie]

Apart from a measure of one's hangover, can anyone explain what the roughness parameter of the vraymaterial does?

I have read the manual (quoted below), and looked at the teapot examples but I'm still not quite sure when I would use it...

"Rougness - this parameter can be used to simulate rough surfaces or surfaces covered with dust (for example, skin, or the surface of the Moon). "

Anyone have any good examples of it in action, or good tips on what types of materials its useful for?

[gafl]

I second that.
It's not very clear for me too...
Gael

[Aldaryn]

I think this is pretty obvious. You can use it for rough surfaces. For example a clay pot. IF you're familiar with the old max oren-nayar shader's roughness parameter, it's pretty much the same I think.

By the way, when I saw it, first, I thought it was a global control for shader roughness affecting the glossiness of everything. Which also would be quite evident imo.

best regards,

A.

[ene.xis]

By the way, when I saw it, first, I thought it was a global control for shader roughness affecting the glossiness of everything. Which also would be quite evident imo.

And somewhat more usefull imo!

[Aldaryn]

Yes, I suppose if we would wanted to stick to a more realistic shader model, a global "roughness" parameter would be the rational choice, but than, I think people would just want to have separated control back.

best regards,

A.

[ene.xis]

yep...thought so as soon as i pressed submit reply!

[peterguthrie]

thanks for the reply Aldaryn. So other practical uses for this would be white plaster walls, concrete, rubber etc?

[rivoli]

haven't really used it myself, but here's a comparison of how the same three teapots would look in one way and the other:

[JeffG2]

Ive used it to nice effect on a lunar surface.

Made the surface loose the CG look and really start to look dusty.

[re:FORM]

Is there any performance hit usinng roughness?

[tricky]

I know this is quite an old thread, but are many people using this 'roughness' control? I was wondering how it scales to a scene?

[Guest]

An old thread again, but there still doesn't seem to be an answer.

[vlado]

It has no relation to the scene scale; it just controls the way the surface reflects (direct) light.

Best regards,
Vlado