Crisp rock edge highlights using Zbrush polypaint?

sybrix

Hi everyone,

I've been working on polypainting some rocks for a tileable wall texture. What I'm trying to achieve is those nice crisp highlights you see on some Zbrush derived textures, for example:


Credit: Marie http://pixel-butterfly.blogspot.com/

What I'm wondering is, do you get a very small brush in RGB mode and polypaint all the edges manually, or is there a way to isolate the edges by some sort of masking option? If you manually paint the edge highlights, do you prefer to use Photoshop for that?

I'm just curious how other people approach this. I was going to just manually paint edge highlights in Photoshop after I bake out the maps, but was wondering how other people do it. I have seen Zbrush screen caps with these beautiful edge highlights on rock, and it made me wonder if that was just the matcap being pretty, or actual handpainted lovin'.

Noors

I think the base is more likely a cavity map generated with Xnormal :
http://www.donaldphan.com/tutorials/xnormal/xnormal_occ.html
(watch at EMB)
It takes the normal map, and generate hilights on convex edges, dirt on concaves. Then, it's a matter of mixing and editing in photoshop.

dirigible

Pretty much what Noors said. Though if you bake out a greyscale curvature map from xNormal you'll get somewhat better results.

Scruples

You can get the same effect by using clay polish, it will mask out creases. So after mashing the clay polish button, invert mask and drop fill some white, or paint it in with a large soft brush where you want it.

If you don't want to alter your mesh you can always save a morph target and switch to it afterwards.

sybrix

Thanks a bunch for the tips guys. Really appreciate it. I'll definitely be trying these methods out hopefully today, I'll be sure to post my progress!

Joopson

Also, Trim Dynamic, set to RGB instead of zAdd or zSub. It'll paint only on the edges. You still have to be careful about it though, because sometimes it doesn't limit painting to the edges well enough, unless using a really weak stroke.

Bek

Also if you expand the masking palette there are heaps of options for masking based on angle, AO, cavity etc, you should easily be able to get a setting that masks only sharp edges / the inverse. I believe there's also a custom mask brush called MAH Mask that was either posted here or on the zbrush central forums that masks planar faces but not sharp edges.

sybrix

So, I got the results I wanted with with baking an EMB cavity map from the normal map in xNormal (Thanks Noors!)

Here's where the texture is at with all the map bakes applied and some painted details in Photoshop:



Working on integrating that grout better, haven't really touched that part yet.

Thanks again for the replies!