ZBrushCentral

Import .OBJ Problem

ZBrush Usage Questions
#1

Hey,
I’m having an issue with importing an OBJ file to replace my old mesh. I exported my model to Maya and UV mapped it. Along the way I must have messed with something or exported it funny because when I try to import the new model at the lowest subdivision level it gives me the exact points error.

What are my options to get this imported in? I took a look at the model and it looks like everything is the way it was when I exported it, aside from the UVs.

Is there a way to copy the highpoly information onto my new basemesh?

Thanks,
-Beck

#2

Sounds like your point order changed.

The best way around this:


  1. Import your new base mesh.
  2. Attach your sculpted hi-res mesh as subtool of the new base base mesh.
  3. Select your new base mesh and divide to the same level as your sculpted mesh.
  4. Use “Project All” to copy the details from the sculpted mesh to the new mesh.
  5. Clean up where needed.
-K

#3

Something else you may be able to do is export another OBJ out of ZBrush without UVs, bring it in to Maya and copy/paste your UVs from your jacked up mesh to this new OBJ.

Also, when you’re exporting your OBJ out of Maya, make sure you tick that option that keeps all verts welded and your model as a single mesh.

#4

Good thought, Dustin. I hadn’t considered moving the UV’s around in Maya, but that might be less problematic than projecting onto a new mesh in ZB.

-K

#5

Thank you for the replies! However, I’m still having some trouble.

I imported the OBJ that I exported from Maya and appended my highres mesh into the scene. For some reason, the highres mesh is twice the size of the imported basemesh! I’m not sure why it did this, since I didn’t modify the mesh in maya at all.

Before I tried the other suggested method, I wanted to make sure that exporting and importing actually worked without me changing anything. I exported the lowpoly basemesh again and imported it into Maya, and then directly exported it back to an OBJ from Maya. When I tried to import it into Zbrush it told me the points were different. I couldn’t find an option to keep the verts welded. I tried this Maya 2008 and Maya 2010.

Any help with either of these problems is appreciated!
-Beck

#6

You probably didn’t do anything wrong. :slight_smile: Zbrush and OBJ scale sometimes does this. Unless you’re modeling to a precise scale, just manually correct your meshes until their almost exactly the same size and use project-all.

Without a detailed examination of your mesh, I’m not sure where your unwelded verts are coming from, but it is likely (IMHO) that there are some unwelded points in your highres mesh, perhaps from the original base mesh you used.

In Zbrush, the Import sub-pallet will have options for merging and welding (Mrg and Weld buttons.)

Given that this might be the case, when importing into Maya, it’s important NOT to merge points as you will change the point-count/order at that time.

Since you have this annoyance (varying point counts), the solution I suggested above (using Project All to transfer the details to your new UV’d base mesh) will likely work. Just scale up your new base mesh to the same size as your current highres mesh once its in Zbrush (Project All depends on the meshes being almost identical in scale.) The maps (normal, displacement, etc.) you generate will be the same when applied the base mesh you had Maya as long as you keep your UVs consistent between the base mesh in ZB and base mesh in Maya, regardless of the scale in ZBrush.

HTH,
-K