ZBrushCentral

Normal Mapping New Topology

ZBrush Usage Questions
#1

Hey, I’ve made a high poly model and did a retopology of it but having a problem. The normal map of the high poly model doesn’t hug it correctly.

I tried copying the UVs from the high poly and pasting to the low poly but the normal map still isn’t sitting on it right. Then I tried flipping the normal map vertical, horizontal, rotating it. Still not working how it should. Am I doing something wrong?

#2

pics or it didn’t happen.

#3

Awaiting some helpful feedback

#4

I take it you created we UVs with the new topology?

#5

awaiting some images of what you’re doing/want to achieve.
or as I said before…pics or it didn’t happen.

#6

No, was that the mistake? Just for reference these were the steps I’ve taken:

  • created a high poly mesh (7 subdivisions)
  • went to the highest and deleted all lower subs
  • created new topoloogy with the Topology Brush
  • split it to a new subtool
  • reconstructed the subdivision levels of the high poly model and left it on the 7th
  • divided and projected on new topology
  • copied UVs from high poly and pasted to low poly model
#7

Yes, I’ve concocted this whole scenario just to get a response to something that I’m really not having an issue with and took the time to post in this particular area of the forum section for the specific purpose of acquiring an answer… that makes sense.

I don’t want to post pictures, simple and plain. If you can’t provide an answer then don’t provide an unnecessary post. There are many talented artists on here and am not confident in the work I’ve done to show it yet. So if you don’t mind, I’m looking for helpful feedback.

#8

Hello Lowk3y,

Generally speaking, the original highpoly mesh won’t need UVs unless you’re doing something more specific with them (such as using UVs to drive Surface Noise, or if you’re happy with the topology of the sculpt and plan on using it’s lowest subdivision level as the final mesh instead of creating a brand new one*). If you’re going to retopologize the sculpt at some point in the process, then only the new mesh will need UVs for the normal map (and it will need UVs to use any form of an image based map). Because the topology and vertex order will be completely different, you wont be able to copy the UVs between these two different meshes.

*Also, the original highpoly sculpt will only need subdivision levels if you plan on using it’s lowest subdivision level as the final mesh. If you’re going to create a new mesh and project the details onto that, then the original sculpt only really needs one subdivision level. You can even get away with using Decimation Master on it at this point of the process, especially if you plan on exporting it and baking the maps externally.

The general work flow is more along the lines of:


  1. Create your highpoly sculpt
  2. Retopologize it
  3. Give the retoplogized mesh a new set of UVs


  • If you’re baking the maps in Zbrush, subdivide the new mesh and project the details from the sculpt back onto it. Once it contains all the detail you want, the original sculpt is no longer needed and you can just bake the normal map from there. The game assets video tutorials here (towards the bottom) should help show the process of projecting and baking in zbrush.
  • If you dont want to worry about projections, just import the highpoly sculpt and your basic lowpoly mesh into a program like xnormal, and have that create the maps

#9

Cryrid, thank you very much for your in depth explanation. You’ve answered my question plus more, you’re the best. Happy Holidays and a prosperous New Year.