I’ve been trying to figure out for years why zbrush unwelds verts in the uvmap on obj export?
In 3d studio max when I import the obj and apply unwrap uvw, all the verts in the map are unwelded!
tool>export>merge then export.
I see, the only reason i didn’t use that option is the warning message it gives when you hold down ctrl over it.
But thanks man i’ll try that 
I’v had the same problem for awhile now and can’t get over it. I always have “merge” turned on in both the import and export tabs. Sometimes when I import back into ZBrush from Max after laying out UV’s each individual UV (or polygon) seems to be rotated or flipped. Each poly in the texture seems to be rotated 180 degrees in either direction. When this happens I have no choice but to delete my higher geometry and resculpt. A real pain and a waste of time.
@riccardoserraiocco
Resculpt everything?..you DO know things that called “Flip V” in the Tool:UV Map palette right?..why must resculpt?..And its a must workflow to flip V the texture/ UV when ever you want to export/ import it into another program.
_Revel
Sorry Revel. We aren’t on the same page here. No problem though. I figured it out. http://www.pixolator.com/showthread.php?t=87406