Question about materials and id maps

Cernantis

As i understand each Id map color means new material and new texture set in Substance. Can i have different materials on same set? How much materials characters and individual props usually have if i aim for PBR? 

oglu

You can have unlimited materials per textureset. Just paint them as you like.
They arnt bound to the ID you get from the id map (highres bake).

A new id from the highres is not the same as a material (textureset) on the lowres.

Cernantis

Thanks, this should clear my questions. I still not completely understand what is the purpose of id maps if texture sets can have different materials.

oglu

Just in case you dont have an id map. cause your highres is just one solid material (color) you have to paint the zones by hand.
Or you would like to have some paint on a wood object. And you wont get that paint from the id map.

Just start to work with Painter and you will find out yourself.

Cernantis

Thanks for replying again! After making textures in Substance, i combined all texture sets in Photoshop (i understand its very common practice, so common there are separate apps for it). Made single material for mesh, imported them to Unreal 4 and it turned out to be fine.
Id maps, as i currently understand, are mostly used in Substance when you want to use separate generators for parts of mesh. For example when you want fine edge wear on only one part, while others are fine with rough edge wear.

oglu

We use it to transfer the material zones form the highres to the lowres.
All leather parts are one id.
All wood parts are one id.
All gold parts are one id.

In the lowres not all elements does have one polyshell.

We dont use Photoshop at all on the current Project.

Cernantis

Yes that's exactly what i've done!  My question was mostly concerning what do you do after all these sets are done, as it turns out combining them in one is fine.

oglu

Thats not the same as we do.
Only the highres mesh does have those ids.
The lowpoly does have only one texture set.

Here at 4min.

https://youtu.be/QJQBaXDKn4w?t=252

Cernantis

Ohhh, i finally get it. 
The colors of low poly model =/= Id maps themselves. They are used to indicate large chunks of mesh, for example torso, head, etc. 
You should have separate high poly that has all desirable materials (as wood, metal, leather) indicated by different colors. This is one IS used for Id maps.
Thanks you very much for explanation.