ZBrushCentral

xnormal/normal mapping process

ZBrush Usage Questions
#1

Hey guys,

I’m sure some of you have used xnormal before, but what I was wondering was can you put in a uv’d low poly mesh, with an un-uv’d high poly mesh.

I’ve watched a few tutorials, and it seems that they have an un-uv’d model in zbrush, and sculpt all the details, but then create a low poly cage and un-wrap that.

But am I correct in saying that both models need to be uv’d inorder for a normal map to be properly created? If so how do people do this,even after they have sculpted all their detail on a un-uv’d model?

It’s kind of confusing, but I hope you guys get what I’m asking

thanks

#2

You can sculpt on a tool in ZBrush whether it has UVs or not. You will, however, need UVs in order to generate any kind of map. The online documentation covers how to create UVs in ZBrush. Otherwise you’re welcome to create your UV layout manually in another application. If you do it in another app, just export the lowest subdivision level of your tool out of ZBrush as an OBJ. Bring it in to your other app and make your UVs. Export it back out of that app with UVs as another OBJ. Back in ZBrush, with your original tool selected and at its lowest subdivision level, import your UV’d OBJ. To do this swap, the two models need to have the exact same number of points, and the point order can not be different. Each vertex has a ID number assigned to it. As long as you haven’t messed with the point order of the mesh, ZBrush should make a clean swap, replacing the one without UVs with the one that has UVs, and preserving any higher subdivision levels you may have. Before you import back in to ZBrush, insure that none of your UVs are inverted or overlapping, as it will cause problems in ZBrush.

#3

Cool thanks Dustin, did not know you could do a swap, that makes things a bit easier.

Couple questions if you could answer them.

What exactly is “point order”?

and what is a good way to check for inverted UVs?

thanks