Micro Roughness

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giannis
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Sat Oct 12, 2013 4:42 am

Javadevil wrote:Looks very much like a fresnel roughness :)
Although, technically it is something much more sophisticated & theoretically founded, you could think of it like being a "fresnel" roughness ;)

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john keates
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Sat Oct 12, 2013 8:50 am

Nice! I have observed this phenomenon before but I had lost hope that someone would implement it in a render engine!

One question: If the ratio of height and width are the same, then surely you get the same effect? In other words, if you double both values then I expect nothing would change. Is that right?

Now there is just polarity, diffraction, holigraphy and a few other things to go ;)

PS. Is there a reference for the kinds of materials that this is relevent for, or is it anything with glossy reflections?
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Sat Oct 12, 2013 10:25 am

One question: If the ratio of height and width are the same, then surely you get the same effect? In other words, if you double both values then I expect nothing would change. Is that right?
no ... you will not get the same effect.
every configuration has its unique effect ... we will not reveal more about it right now but you can be sure its based on real physics like everything else in Thea.

Greetings Patrick
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I too, can see the stars on a desert night, and feel them. But do I see less or more ? "

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john keates
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Sat Oct 12, 2013 3:39 pm

patricks wrote:
One question: If the ratio of height and width are the same, then surely you get the same effect? In other words, if you double both values then I expect nothing would change. Is that right?
no ... you will not get the same effect.
every configuration has its unique effect ... we will not reveal more about it right now but you can be sure its based on real physics like everything else in Thea.

Greetings Patrick
Cool, it makes sense that every setting will be unique of course... I was just trying to get my head round how it worked.
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Theodor
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Sun Oct 13, 2013 8:53 am

hi,
The micro roughness is new thing for me quite frankly i didn't know that something like that exists. After you post i have been on strange hunt for material with this effect and i failed to find any other than displays. Although i succeeded to make my neighbor wonder about my mental health, while checking materials on my car for micro roughness. :P

d.
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Sun Oct 13, 2013 10:12 am

An anti-glare screen is probably the typical surface to study the phenomenon.

To study this, you need to have a surface (or object) that is illuminated from a fixed point and then observe the surface from varying angles. If lighting angle changes, you probably do not notice the effect. Counter tops, long corridors... maybe look on those as with them it's easy to have a fixed lighting and only you can move (without changing the illumination) ;)
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Mon Oct 14, 2013 9:52 am

Very nice feature and I believe it can be used in more situations as we think right now. As MrWip's example shows it can be necessary for all kinds of reflective floor materials.

my question about micro roughness
how much does it influence render times?
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patricks
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Mon Oct 14, 2013 11:43 am

archplanviz wrote:Very nice feature and I believe it can be used in more situations as we think right now. As MrWip's example shows it can be necessary for all kinds of reflective floor materials.

my question about micro roughness
how much does it influence render times?
render times are very similar, I did not notice any render time penalty with micro roughness.

Greetings Patrick
" Poets say science takes away from the beauty of the stars - mere globs of gas atoms.
I too, can see the stars on a desert night, and feel them. But do I see less or more ? "

Richard P. Feynman
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Mon Oct 14, 2013 8:28 pm

thx patrick for the info
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