UV Mapping - From Maya to Zbrush to Substance Painter

Benja_3d

Hello,

a month ago I started discovering 3D and its many software: Maya, ZBrush, Substance Painter/Designer, UE4... If a lot of things are complex, they always (even Zbrush...) feel pretty logical to me... but the UV Mapping is apparently more confusing than I thought.

Here's what I would like to do: Maya to create a lowpoly -> Zbrush to refine it into a highpoly -> Substance painter for texturing

I've seen quite a lot of different ways to go about it on YouTube and other platforms:

- Create lowpoly model in Maya -> Zbrush to create highpoly model -> Duplicate it -> Zremesher -> UV Master to have UVs of a lowpoly version, copy/paste them on the high poly version -> Export 

- Create lowpoly model in Maya -> Zbrush to create highpoly model -> Back to maya for a Retopology and create UVs -> Export

- Create lowpoly model in Maya -> create UVs in Maya -> Zbrush to create a highpoly version of it -> Export 

I've read people telling that for Substance Painter the highpoly doesn't need UV's as it will use those of the lowpoly. I've read people telling that the inverse: The highpoly needs UV. 

I must say... I'm quite lost. Any info will be greatly 

Thanks a lot for your time.

zachagreg

Highpoly doesn't need UVs at all. Uvs on a highpoly will only matter in Zbrush as it gives you a little more control with tools in Zbrush specifically noise maker and some of the other tools dependent upon topology. Most of the time as an environment artist I don't do that. As for which workflow works best for you is a matter of what is being made and preference.

Find 3 props you want to make and then try each worflow out for yourself and see which one suits you best.

I can tell you a general thing right now the the first method is good for organic shapes but UV master is never a professional UV pack/Unwrap and won't give you the precision and optimization of a hand pack and unwrap.

Second method is common for characters and creatures, sometimes props need it as well but I try to avoid retopo as a step and rather focus on maintaining my subdivisions in Zbrush for unwraps. It's a lot easier to subdivide your geo in Maya/Max and then use the deformed lowpoly from your highpoly sculpt. Then UV that.

Third method is pretty much if you maintain your subdivisions perfectly or your not using Zbrush for big form changes, gun metal damage and corner damage kind of stuff or greebles and surface damage. Basically if your not changing silhouette too much with your sculpt this will work fine.

Also be careful in terms of what you watch on youtube as sometimes artists, when working at home, will work dirty because they're just trying to make art. More creative expression lends itself sometimes to doing things that wouldn't necessarily be okay in a production environment.

Dihemi

Your low poly mesh (end product) will definitely need UVs. Whether your high poly mesh also needs them depends. You mention you'll use Substance Painter, so probably not.

In general, when starting baking, you want to have a high and low poly mesh. As long as you only bake mesh data (normals, height, curvature, etc.) from your high mesh onto your low mesh you only need UVs on your low poly mesh. After baking (in Substance painter) you'll use those baked textures (normal, height, curvature, etc.) to start texturing/generating your base colour, roughness and metal textures. Those textures are then applied on your low mesh.

If you're using Substance painter that's most likely the only workflow you'll need (a.k.a only UV the low poly mesh, bake the high data on low mesh, proceed texturing on low mesh).

However, sometimes, for various reasons, people will texture (base colour, roughness, etc) the high poly mesh first, and then bake all that data (normals, height, curvature AND base colour, roughness, metal, etc) to the low poly mesh. In that case, both need UVs. Otherwise you can't texture the high poly to begin with. But Substance painter isn't made for that kind of baking process.

As a starter I would advice to create your UVs (on your low poly) as late as possible; right after both your low and high are finished, just before you'll do your baking and subsequent texturing. It will prevent double work. Using Substance Painter, you'll only need low UVs.

I hope this helps.

Edit: woops ninja'd by Zachagreg.

Benja_3d

zachagreg said:

Highpoly doesn't need UVs at all. Uvs on a highpoly will only matter in Zbrush as it gives you a little more control with tools in Zbrush specifically noise maker and some of the other tools dependent upon topology. Most of the time as an environment artist I don't do that. As for which workflow works best for you is a matter of what is being made and preference.

Find 3 props you want to make and then try each worflow out for yourself and see which one suits you best.

I can tell you a general thing right now the the first method is good for organic shapes but UV master is never a professional UV pack/Unwrap and won't give you the precision and optimization of a hand pack and unwrap.

Second method is common for characters and creatures, sometimes props need it as well but I try to avoid retopo as a step and rather focus on maintaining my subdivisions in Zbrush for unwraps. It's a lot easier to subdivide your geo in Maya/Max and then use the deformed lowpoly from your highpoly sculpt. Then UV that.

Third method is pretty much if you maintain your subdivisions perfectly or your not using Zbrush for big form changes, gun metal damage and corner damage kind of stuff or greebles and surface damage. Basically if your not changing silhouette too much with your sculpt this will work fine.

Also be careful in terms of what you watch on youtube as sometimes artists, when working at home, will work dirty because they're just trying to make art. More creative expression lends itself sometimes to doing things that wouldn't necessarily be okay in a production environment.

Thanks a lot for all the infos!! 
So as an environment artist, would you mind telling me what would be your go to workflow? I'm mainly interested in creating assets for small environments. 

Benja_3d

Dihemi said:

Your low poly mesh (end product) will definitely need UVs. Whether your high poly mesh also needs them depends. You mention you'll use Substance Painter, so probably not.

In general, when starting baking, you want to have a high and low poly mesh. As long as you only bake mesh data (normals, height, curvature, etc.) from your high mesh onto your low mesh you only need UVs on your low poly mesh. After baking (in Substance painter) you'll use those baked textures (normal, height, curvature, etc.) to start texturing/generating your base colour, roughness and metal textures. Those textures are then applied on your low mesh.

If you're using Substance painter that's most likely the only workflow you'll need (a.k.a only UV the low poly mesh, bake the high data on low mesh, proceed texturing on low mesh).

However, sometimes, for various reasons, people will texture (base colour, roughness, etc) the high poly mesh first, and then bake all that data (normals, height, curvature AND base colour, roughness, metal, etc) to the low poly mesh. In that case, both need UVs. Otherwise you can't texture the high poly to begin with. But Substance painter isn't made for that kind of baking process.

As a starter I would advice to create your UVs (on your low poly) as late as possible; right after both your low and high are finished, just before you'll do your baking and subsequent texturing. It will prevent double work. Using Substance Painter, you'll only need low UVs.

I hope this helps.

Edit: woops ninja'd by Zachagreg.

Thanks a lot for the time you put to explain all of this to me. It makes a lot of sense. 

zachagreg

Benja_3d said:

zachagreg said:

Thanks a lot for all the infos!! 
So as an environment artist, would you mind telling me what would be your go to workflow? I'm mainly interested in creating assets for small environments. 

So for smaller assets, particularly props and assets like that.

I would make my lowpoly first and put that on a layer. Then make a subdivided version (not subdivided in the sense of highpoly modeling just edge loops so that Ill have even quads in Zbrush. If I know I'll need a pattern on a specific piece say a wicker basket or something of the like I will UV that for using noisemaker. Take the Subdivided mesh into Zbrush and start making my highpoly by up the subdivisions and sculpting.

I will then export or decimate and export the high (depending on how heavy the mesh is) the entire time I'm sculpting I will try to maintain my subdivisions as best as possible, sometimes you can't so be aware of that. Sometimes you will have to ZRemesh and reproject because of Sculptris or Dynameshing.

But after highpoly is done and exported I'll drop all my subdivisions and export that as my low poly. Now you can do one of two things. Depends which is easier. You can take your original low poly and cut in the silhouette changes using snapping and having the Zbrush lowpoly floating on top of it to snap vertices. This works really well for very low poly requirements as you don't have the subdivisions. Or you can just remove the subdivision you know you don't need from the Zbrush lowpoly export. When you maintain your quads this is easy but can be time consuming on larger or more complex props.

For hardsurface stuff I rarely leave Max honestly. Because my lowpoly generates my high and vice versa with SubD modeling. A lot of time I will also forgo Zbrush on props if I can do the damage/ surface details as floaters in Max or textures in Substance