Imperfections / Roughness maps

[miacreed]

Hi all, hope everyone is well + thanks for the help yesterday,

I'm trying to work with roughness maps to add imperfections to my materials- I've downloaded an imperfection/roughness map from Quixel and am trying to attach it to an empty base material but I'm seeing no change in the render, even though the Roughness map is set to 1.0. Any ideas as to why this is?

Follow up q: Most materials I work with normally have a preset roughness/glossiness map. I was wondering how I would be able to add an imperfection on top of this native roughness. Since I haven't been able to get the imperfections to work at all I haven't tried to mix it with another map yet, but I see this becoming an obstacle down the line. I was thinking maybe use a CoronaMix or Composite map to mix the two? Would the imperfection map go in the Top, Bottom or Mix slot?

Thanks in advance!
Best
Mia

[pokoy]

You need to have something being reflected, if your environment is too uniform, there's no (or too little) difference in places where the reflection is glossy vs where it's rough.
Best to check the effect would be to use a light close to the surface, this will probably show that a map is present.

The strength of the effect is being controlled by the control amount further down in the material properties dialog.

[romullus]

Follow up q: Most materials I work with normally have a preset roughness/glossiness map. I was wondering how I would be able to add an imperfection on top of this native roughness. Since I haven't been able to get the imperfections to work at all I haven't tried to mix it with another map yet, but I see this becoming an obstacle down the line. I was thinking maybe use a CoronaMix or Composite map to mix the two? Would the imperfection map go in the Top, Bottom or Mix slot?

Corona mix, composite, or regular mix - any of those maps are well suited for the job, you can use whichever you want. As for the textures order, for some blending modes it does not matter, for others it gives different result, but neither will be right, or wrong. Feel free to experiment and see which mode and map order will give you result that you like. You can't go wrong here.

[MitchRaymont]

This may also be of use to you - https://help.poliigon.com/en/articles/2332731-using-poliigon-overlays-to-add-surface-imperfections-in-3ds-max-with-corona