Need some advice/help... zbrush/maya

Fournish

Hi! I'm new to the forums and I've been messing around lightly with 3d over the last few years.. Not actually dedicating tons of time until recently. I'm still learning a lot! and polycount helps a great deal. Anyway....

I had built a base mesh for a bag in maya then had taken it over in zbrush. Brought the subd up a couple and did some detail then unwrapped it and polypainted it... But now I've hit a snag.. I have way to many faces on the bag (want to make the bag game ready) and I just think I did things in the wrong order because I can't figure out how to get the model down in count but keep my nice looking texture I exported from the polypaint. I'm most likely over complicating things here but I am a noob..

Bartalon

If you brought a base mesh over from Maya, you simply need to return to your lowest subdivision level from the Geometry subpalette. If you have lost your base subdivision you will need to get it back by retopologizing. If you deleted your lower subdivisions at some point, you can attempt to get them back by clicking Reconstruct Subdiv in the Geometry subpalette, otherwise you'll need to retopologize some other way.

Your texture should look the same on your base mesh as it does at the highest subD level provided you have the Texture On button activated as you do in your screen shot.

If you want to export your texture map from ZBrush, you just need to click Clone Txtr (underneath Texture On) then go up to the Texture menu palette, click the FlipV button (Zbrush likes to bake textures out upside down for some reason), then click the Export button under the same menu palette.

You can follow the same series of steps for a normal map and displacement map (use the Alpha menu palette for exporting a displacement map instead of the Texture menu palette).

Fournish

Thank you for these really clear instructions it means alot! I'll try my hand at retopologizing it.. Could I just use zremesher for that? I tried once but it gets rid of my texture.. So i would just have to redo it im guessing?

Bartalon

ZRemesher will work for retopologizing, yes. Because it destroys your original mesh, you will want to work on a copy of your original sculpt in case you want to go back to your original. You can use ZRemesher along with the ZRemesher Guides brush to help guide the resulting edge flow. You can see an example in this video at about 9:50.

As for keeping your polypaint data, you can use a neat trick combining ZBrush and xNormal to transfer your high-poly polypaint data to your low-poly, UV mapped model. Tutorial here.

If your matcap in ZBrush has a strong effect on the appearance of your textures, you can also follow this tutorial on how to export your matcap to a flat texture map. It's a bit dated but still should work. It's the only bookmark I have on hand right now