Exporting polypaint for retopo, texture looks way different?

ahendowski

So I exported an .obj of a character I'm working on. I polypainted him and got him all set up, but when I exported him to TopoGun, his texture tones changed to a grey, even leaving out a part on the back of the arm. Can anyone help?

http://imgur.com/a/btChG

Bartalon

This is probably due to two things: your matcap in ZBrush is set to Basic Material rather than Flat Color, so it will appear to have more defined shadows/highlights than there really are, and a slightly different color as well.

Additionally, if there are areas on your model which do not have polypaint data, it will default to the color that is set to the right swatch just below your color picker in the left tool bar. This may explain the white areas at the back of your model's arms.

These two things do not translate to other software applications, as they are just previews within ZBrush. There are ways to bake out a base color and the matcap details into a diffuse map which require your model to be UV mapped.

ahendowski

I think that's it, I fucked up lol dammit. Oh well, more texture practice. I'm seeing super white dots, the matcap was definitely making me think I was texturing where I wasn't. I'll get it right this time.

Thanks so much. For standard polypaint texturing, is FlatColor the best matcap for that?

Bartalon

If you want the truest representation of your diffuse colors then you should use Flat Color. Most of the other materials will overlay artificial shadows, highlights, colors, and other effects like specularity, reflectivity, etc.

ahendowski

So one other thing, how would I go about baking out the matcap? Do I need to retopologize, then import the low poly / unwrapped model into the high poly sculpt? How do I go about doing that after I retopologize / uv unwrap, or am I completely wrong?

I'd love to use my UV maps and transfer the matcap / diffuse onto the actual UV sheet instead of using vertex color.

Bartalon

You will need an unwrapped low poly model. If you didn't start with one you'll need to use the Project All operation to transfer your high poly and polypaint details to your low poly model. From there you can use this plugin (I can't confirm this works on latest versions of ZBrush) or this manual tutorial to transfer your matcap details. This should also include whichever default color you have set during the process, so you can fill in the empty spots such as the back of the arms.