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Problem with Zbrush AUV Tiles

ZBrush Usage Questions
#1

Hi everyone.

I have a question about xnormal and Zbrush AUV Tiles, hope to find help here, because it drives me mad.

I export a low poly mesh and a high poly from Zbrush with the AUV Tiles. Then I wanted to bake a normal and ao map with xnormal.

When I apply the maps to my low poly model in maya, It lloks alway crappy, because of the seams. Every face has ugly seams around it.

So my question: is it possible to use the AUV Tiles from Zbrush with Xnormal ? Does anybody knows the trick ? Or do I waste my time with this ?

Perhaps anybody has got a link to a tutorial I missed.

#2

AUVTiles is not a good mapping format for use with a Tangent map. The reason for this is that the math behind tangent maps dictates that normals are flipped when crossing UV seams. Since AUVTiles results in every polygon being its own individual square on the UV map, that means that a Tangent map will have lots and lots of seams. It doesn’t matter whether the map is created in ZBrush or another program, the math of the Tangent normal mapping method is consistent and you will always get visible seams when crossing a UV seam.

#3

So that what do you recommend choosing when creating UV maps if its not the AUVTIles?

#4

You should unwrap using pelt, cylindrical, planar and whatever other methods you prefer so that you minimize and control where the seams are. Remember you can stitch different groups of uv’s together and hide seams where usual lines would be eg. stitching seams. The new PUV seems to work better in 3dsmax on not leave outlines but this is still not an auto-uv solution for normal maps.

#5

I´m agree with pixeldamage, since the last version of zbrush, 3.5, when I do the uv in zbrush is with PUV, it works very good.

by the way, now you have uv master which is incredible!

#6

I found that by disabling texture filtering it helped fix the seams in the viewport of max but still had issues rendering (but you could also try hitting “fix seams” in the texture menu of zbrush before export). I found it temperamental though and think i ended up using PUV instead as it had less seams. Shame its not really that artist friendly getting assets outside of zbrush at the moment. Fingers crossed GoZ will fix all that when it comes out on PC… one day.