How to create Roughness/Glossiness maps

Raildex

Hi there. I'm very new when it comes to texture creation.
I'd like to know how I create the Roughness/Glossiness map.

The Normal Map seems to be a starting point, since it may contain small details.
How do you create your roughness/glossiness?
I could also think of a blank/white roughness map, since rocks for example have no reflectivity.

Obscura

If you think that rock has no reflectivity, you should start by reading some pbr tutorials, because your concept on how shading really works is wrong. Everything has reflectivity, even they are standardized into 2 major categories. More in the link.

This writeup covers some good bases:
https://www.marmoset.co/posts/physically-based-rendering-and-you-can-too/

ZacD

Roughness ≠ reflectivity. Rocks have reflection values and they are not 100% rough either. 

Reflectivity is not related to roughness or glossiness at all, it's a separate value.

A dusty rock is going to be very rough, maybe even completely rough, but a smooth rock from a river might actually be pretty polished and pretty glossy. Rocks in caves tend to be pretty smooth and more glossy as well, even when no longer wet. 

Raildex

Thanks for the explanation although I haven't asked whether a rock has reflectivity or not.

Obscura

The tutorial I sent, would teach you about your original question... PBR and roughness is fully related to each other and if you want it to work/look nice, first you'd need to understand how pbr works.

gsokol

Raildex said:

Thanks for the explanation although I haven't asked whether a rock has reflectivity or not.

Cmon man


The point is, in order to properly paint these maps, you need to understand what they do.  The reflectivity was pointed out to you because you seemed confused on the difference between roughness and reflectivity.  

That link that @Obscura sent you would be a great place to start.

musashidan

Raildex said:

Thanks for the explanation although I haven't asked whether a rock has reflectivity or not.

Remember, people here are trying to help you. You may not have asked but, what you stated: "I could also think of a blank/white roughness map, since rocks for example have no reflectivity." - shows that you don't understand the concept.

As mentioned above, everything on the planet that is affected by light has reflection. As well as studying the links obscura posted I would recommend downloading some materials from Substance or Quixel and studying the Roughness maps, and how they relate to the other maps. A roughness map would never have a pure black/white value as there will always be value changes at the micro-surface level. IMO, the roughness map is the most important map in the whole workflow as it is the map that most relates to us what the material actually is, i.e: rubber/stone/hard plastic/etc.

NoRank

It's pretty simple actually, roughness/glossines map is just a simple map that will have grayscales values. I don't really think that there will be a time where you will use full black or white thought.

Marmoset website and allegorithmic have some really good articles that explain it in depht if you want to know how it actually works.

Raildex

I do understand what a roughness/gloss map is. That's not the problem.
I just wanted to know what the common workflow is to create them.

About the "blank" roughness map: It was an example, because Rocks/ Stone have a high roughness and thus only few parts are grey-ish.
It depends on the case of course.

EliasWick

Raildex said:

I do understand what a roughness/gloss map is. That's not the problem.
I just wanted to know what the common workflow is to create them.

About the "blank" roughness map: It was an example, because Rocks/ Stone have a high roughness and thus only few parts are grey-ish.
It depends on the case of course.

Hey,

Once you understand what these maps do, you have 3 alternative:

* Create them by hand = You can use built in Photoshop filters to simulate and create these maps. (This is really hard to do and may be inaccurate.)
* Use software & plugins to generate a map from texture = Quixel or Substance, Some websites allow you to generate the maps you need.
* 3D Application Baking = Baking high poly to low poly. 

One last thing, if you want to create something that looks good, I suggest that you listen to all of the guys above. They know what they are talking about.