Hello, guys. I hope you are all doing well this days.
I have a little problem with my project and cannot find a workaround. Maybe someone will help me. Actually, the problem is quite old since I encountered it when started using Zbrush.
A bit of history. As many of you probably know that Zbrush always had problems with managing UVs. Till the recent updates ZBrush couldn’t properly smooth UV coordinates and was keeping them non-smoothed. To make it even more confusing, there were SmoothUV buttons in Normal/Displacement sub-palettes to average coordinates when baking maps, but it appears that smoothing was performed based on current and not from the lowest subdivision level. So if you bake Displacements from 1st level your maps would appear nice and not distorted, but when you bake Normal maps from 4th level, then Zbrush will try to smooth very dense UVs that will result in still angular (distorted) texture. Plus when baking polypaint there is no Smooth UV’s option at all.
Now they added SUV and ReUV buttons in Geometry subpalette and it might look like the end of the headache. But there is a problem. When you subdivide your unwrapped basemeshes, export/import it with GoZ, reconstruct subdivision levels and perform other numerous operations it constantly SHRINKS and SHIFTS UV coordinates so at the end of sculpting they differ a lot compare to those in basemeshes. And this changes might cause huge problems. The obvious solution is to make all the work inside of Zbrush first and then transfer UVs from previously stored low-poly. And this leads to another problem. Zbrush does something to meshes that breaks this workflow. I tried copying UVs straight inside Zbrush via UVMaster, also in Maya and in Blender. It transfers coordinates from basemesh to 1st subdivision level, but each polygon becomes a separate UV island that explodes when you try to sew it. It appears like Zbrush messes vertex order though I’m completely sure that I preserved the order during import/export.
I have an already finished model in Blender with subdivision and other modifiers that I would like to paint in Zbrush. Then bake polypaint and use this texture in my original model.
So did you encounter a similar problem? And if so, how do you deal with it?