Maya Normal Map from Zbrush issue

# 1 16-06-2011 , 02:45 AM

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Here's my workflow:

- Base mesh created in Maya 2009
- Added high res detail + color map in Zbrush, created normal map from high res detail
- Exported normal map back into Maya, using original base mesh

The normal maps look all messed up in Maya, as you can see from the render. I have tried flipping the Green channel, reducing the bump depth and making sure that tangent space normal is checked and it still looks weird. Still can't figure out what is going on. Any ideas?

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# 2 16-06-2011 , 03:45 AM

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Hmm. When u say in step 3 you exported the normal map from z and used the original mesh, do you mean you didnt export back the low level mesh from zbrush?

Also how did you create your uvs?

Applied any mesh smooth/approximation editor?

Last edited by ben hobden; 16-06-2011 at 03:49 AM.

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# 3 16-06-2011 , 08:45 AM

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Looks like to me that the normals are flipped or the UVs need flipping...........dave

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# 4 16-06-2011 , 02:33 PM

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Hmm. When u say in step 3 you exported the normal map from z and used the original mesh, do you mean you didnt export back the low level mesh from zbrush?

Also how did you create your uvs?

Applied any mesh smooth/approximation editor?

Originally Posted by ben hobden

Either with the original base mesh from maya or the low level mesh at level 1 from ZBrush, it doesn't matter, it still looks bad. UVs were created with UVLayout and are fine since the color map looks fine. I am using the smooth mesh preview in Maya but I have not used the approximation editor since that has frequently caused issues with my models.

UVs match up fine with the mesh, I already correctly flipped the V when exporting from ZBrush. Again, I tried flipping the G channel in ZBrush.

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# 5 16-06-2011 , 02:39 PM

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How quickly did you go up your subdivision levels in ZBrush? Comparing the two shots, the areas that have most recognisable detail are the areas where there is densest geometry (around the eyes/mouth). It looks almost as if there is high level detail there, but no lower level info to sustain it... did you spend much time working at the lower/middle subdivision levels?

Edit: Have you tried exporting out your mesh at maybe level 2,3, or 4 from Z...to see if you get better results off of those?

Last edited by ben hobden; 16-06-2011 at 02:45 PM.

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# 6 16-06-2011 , 03:12 PM

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None of the higher subd levels gives any better results, which means that its not a problem with the mesh itself but the normal maps. I shouldn't have to up my polycount by 4X or 16X to get decent looking normal maps anyways.

Does it matter if I was working at the highest level in ZBrush? Doesn't the high res detail get transferred down to the lower subD levels as I add it in?

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# 7 16-06-2011 , 03:22 PM

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To be honest...I dont know for sure... but I think it does. You would think the high level stuff would just filter down wouldnt you....but have you noticed how sometimes you erase detail at one level, and evidence of it is still there at others? And it stands to reason doesnt it...otherwise you wouldnt have the levels in between, and all the manuals would just say...'import your mesh...divide it as much as you can......and sculpt.'

My hunch is that this is maybe more the reason... not a technical issue...but a 'process/workflow' issue....

...but thats just a hunch. I cant think of any other reason, other than if you have used the wrong settings on exporting your normal map/obj...but you seem to be on top of those and aware of most of the other common solutions...

Did you work almost exclusively at the highest sub-d level?

Last edited by ben hobden; 16-06-2011 at 03:52 PM.

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# 8 16-06-2011 , 04:23 PM

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I really don't think it matters that I worked in the highest subd resolution. Being able to go back and forth between different subd levels and have the changes transferred is such a core feature of ZBrush. It would be so much more of a pain in the ass if I had to worry about what the mesh looked like at each level.

Thanks for your help; I guess I'll keep looking at the zbrush export settings, or maybe maya doesnt know how to interpret/display the map correctly.

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# 9 16-06-2011 , 04:34 PM

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I would say that I think it is important to be aware of your mesh at the different levels. I think of it like a house of cards...each row needs to be strong enough to hold up the next level. But, I'm still learning myself. If you find a solution, it would be good to know.

You could always try a search for similar threads around this issue on here...good luck.

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# 10 16-06-2011 , 07:21 PM

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What are your maya setting set to, are they set to tangent space. have you checked your norms.........dave

Edit:also try deleting the normal map conection in the shader then do it manualy

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Last edited by daverave; 16-06-2011 at 07:29 PM.

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Maya Normal Map from Zbrush issue

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