ZBrush - Need an advice on sculpting (UV's and texturing trouble)

lupuslup

Hi!
I'd like to ask you about an advice on sculpting models for exporting.
I am making models only for still/static images, because I'm very bad at UV's, retopo and baking out.

I'm trying to handle the textures and UV's in ZBrush for a few months now, but it just doesn't work - I've spent a lot of time to learn from the various professional tutorials, tutorials on youtube and such.

Let me first explain how do I work in ZBrush:
- starting off with the basic shape, modelling etc.
- dynameshing a few times blocked model to make finer details
- polypainting
- posing the model
- usually dynameshing again for the final details
- making a duplicate with low res (for example 30k) then projecting out the original model (3-6 mln polys) 
- (And here begins the problem) creating UV's with the UV Master, when baking polypaint textures are blewn away/ or very messy

I'm trying different methods on UV's, letting the UV Master to do the whole thing or I'm covering sides manually with the "Protect" and "Attract" commands or by polygroups

I have an example here, this is my model from november (Warning, slightly NSFW) - https://skfb.ly/VQPz
I couldn't work out messy baked textures, so I have left it without UV's and maps I also haven't decimated it.

Sometimes to go around with the UV's I'm decimating the model before putting on UV's and textures but it doesn't work out always. 

I can use external programs if it's necessarily for a better workflow (i've already tried with Topogun, UVLayout and 3D Coat)

lupuslup

Anyone more experienced to share the knowledge?

musashidan

From your explanation I'm guessing that your problem is that you're trying to project polypaint data onto a low-poly mesh that hasn't got enough verts to support the information. Polypaint is essentially vertex painting so you need a very high vert count to retain the detail.

You need to divide the(already unwrapped) low-poly up to a similar vert count as the high-poly>project the texture onto the low through all the levels>save out the texture>export the low>apply the texture to the low.

lupuslup

@musashidan I'm doing exactly what you're saying plus it's coming out messy when it's posed already, if it's symmetrical it's fine but I want to know if there's any way to lay UV's on posed-already models.

I guess that I'm doing just something wrong - not at the correct way
Sorry if my explanations aren't clear enough

cryrid

I think you might have an easier time if you adjust your workflow to a more classic approach that uses subdivision levels. 

Block out the base model however you need to. This can be done with zspheres, dynamesh, or an existing basemesh. Don't worry about sculpting in fine details, just make sure you establish all the main forms of the sculpt. 

Once you have that, then retopologize the mesh. Manual retopology will give you the best results, but ZRemesher will suffice for now while you get used to using zbrush. 

Once your mesh is retopologized, then you can start to subdivide it to sculpt in finer surface details, polypaint it, and pose it. A benefit here is that you can step down to a lower subdivision level, pose it, and then step back up and still have the details. 

If this is for illustration then it shouldn't matter if you UV before or after posing. You can give the mesh UVs immediately after the retopology stage, or wait until you have it posed and sculpted. I'd probably wait until afterwards just to keep the working size down. 

The quality of your texture will depend on:

1. The resolution of your texture.

2. How efficient your UVs are laid out to make use of that texture size.

3. The overall quality of your polypaint. This is based on the 'flat' material only; matcap/lighting data will not get baked to the texture.

3. Which subdivision level you are on when you convert the polypaint to the texture. 

lupuslup

@cryrid I don't like working with subdivision levels, I've got used to using dynamesh and projecting everything on the final stage
Merging multiple layers into one looks awful without using a dynamesh, for example if you're merging character parts




UV's got only one island and looks very messy also there are bugs which I've tried to repaint with the Projection Master but it has failed at the end
I've tried to lay out UV's manually in the 3D Coat but while the model wasn't symmetrical anymore (because it's posed already) I've gave up