Ineffective specular roughness

Started by N-drju, May 22, 2020, 07:52:36 am

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N-drju

I'm afraid something is very wrong with how the specular roughness on a reflective shader works. Either that, or me not getting the concept.

As far as I know, specular roughness is how "clean" a reflected surroundings are. Like looking into the mirror vs. looking at a matte screen.

If above is true, then why each SR setting I try renders perfectly visible, non-blurred, undistorted image of an object's surroundings? ::) Just take a look:

SR 0.1.png

SR 0.45.jpg

SR 0.8.jpg

In every single case, the cube and the tree are unaffected. Only covered with a hazy veil. Seems like sunlight is the only thing affected.

A single reflective shader was used for these images.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

Nala1977

something clearly wrong here, that is not how it is supposed to work

N-drju

I mean, of course - one can use displacement to make required distortions but, for some reason, I was certain that SR could provide this effect on its own.

Come to think of it, one doesn't even need this feature in the reflective shader if fractal displacement does just the same and better yet.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

WAS

Specular is "Specular Highlights". Direct light reflecting at the camera/viewer. It's not a mirror reflection. You can't see into direct specular highlights and see reflection usually. In fact you'd get eye damage. Lol

Matt

@N-drju The Path Tracer renders these materials much more realistically, applying the specular roughness to the ray traced reflections. The Standard Renderer, on the other hand, cannot do this. If you're rendering with the Standard Renderer, the best you can do for rough materials is to turn ray traced reflections off, and then it approximates the reflections with the GI cache.
Just because milk is white doesn't mean that clouds are made of milk.

N-drju

Thanks Matt, it indeed looks better.

Though I admit that building a "legacy" rough surface creates a nice effect as well and more controllable too.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

WAS

There is also slightly roughing the surface of standard renderer objects with microdisplacement to blur/roughen reflection with ray traced reflections.

N-drju

Yes, this is the way I'd go for when not in the PT mode. In fact, standard renderer with displacement still looks better than PT roughness on several accounts.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"