Microdetails on highlights

[dastagir]

Hi there,

I'm practicing in some advanced materials and trying to recreate the effect like on pic 1. When bump details are visible only on highlights areas.

It doesn’t look right if I put only coronaNormal in the bump slot. So I decided to use Fresnel Falloff like in coat material. It looks better but not as detailed as I want. Even with 8k texture.
I tried to use the same map with falloff in gloss slot to accent scratches but it doesn't help and scratches start to appear on midtone areas even if I tweak curve.
Also, I'm interested in effect when dirt map (gloss.) is visible only on highlights not on a whole surface.

So what is the best walkthrough to archive the same result as on pic1? Maybe I don't understand this effect and how it works and do everything wrong..

[JViz]

you could try to add the details in the glossiness slot instead of the bump map.

[lupaz]

I’m afraid you can’t get micro detail with bump maps in corona unfortunately.

[dastagir]

Yes, I've found a thread about this recently. So, as JViz said the best solution for me now, is mixing some grunge with scratches and use them in gloss slot with a veeeery little bump.

[JViz]

Yes, I've found a thread about this recently. So, as JViz said the best solution for me now, is mixing some grunge with scratches and use them in gloss slot with a veeeery little bump.

Yes, try this: add output and color correction maps in anisotropy and anisotropy rotation and instanceThe glossiness texture in them, experiment with these, it can produce very nice results.

If you think about it scratches/smudges always have a direction or more in them, that's why you add the anisotropy effect. That will give you the microdetail effect

[sprayer]

similar topic maybe will be helpful
https://forum.corona-renderer.com/index.php?topic=22272.0

[dastagir]

Many thanks for the help! I got satisfactory results and it was really important to use proper texture.

[actrask]

I was just reading an article which made me think of this post. Would 'bump roughness' be the proper way to solve the micro details on highlights?

About a third way down has a good example: https://renderman.pixar.com/stories/cars-3