Normal Map Seam Problem


I am at a loss as to why this is happening but when I go to generate Normal Maps in Zbrush I am getting a seam at edges of UV islands. Does anyone have any idea why this is occuring? The same thing occurs if I bake normal map in xNormal from hipoly version of vest to low poly vest. I assume if I simply rotated the vest front island 180deg the normals would match front and back due to the front and back uv islands sharing the same orientation however this is unpractical for other models where you need to rotate stuff to different orientations in order to get an efficient packing of UV islands. I am totally stumped:( I’ve looked all around for a solution to no avail:(

Here is a picture of issue/unwrap:

Thanks in advance guys,


normals could be inverted or that uv island is flipped
check normals direction both on high and low and see if all islands as the same orientation.

1 more thing
i see you have only one side of the vest, are you using the same uv space for the right and left ?


flip one of your shells so they match each other - one is upside down so the normal map fake is reversed.

you might still get seams of they don’t align in UV space, though. read this:


CGG and CGBiege - the model consists of unique detail for front, back, and each side respectively. I simply cut the vest into two pieces for the unwrap (seams on sides of vest). The problem was that the front of vest island didn’t have the same orientation as back of vest island. I was under the assumption that ZBrush would take this into account automatically and render normals for the front of vest island upside down. I had to manually rotate front island 180deg so it had same orientation as back island and they then had matching island orientation.

Thanks for your effort in responding.


Hey thanks man for this link. I didn’t realize UV Layout could square up edges of UV coords like this. Perfect solution!



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