I’m trying to figure out how to produce a normalmap with ZMapper. I pick a UV group and start up ZMapper. I load up one of the Maya-based presets; Maya_ObjectSpace_BestQuality.zmp, to be specific. I don’t even know the difference between any of them yet or what any of the settings mean… still, apart from that I follow the tutorial on ZClassroom for using ZMapper to generate it, setting the mesh to the lowest level and then hitting “create projected normalmap.” When it finishes, I get a normalmap of the topology of the lowest subdivision level. What gives? How do I tell it to map the highest subdivision level to the basemesh? Any help would be much appreciated. 
ZMapper will always create a map based on the differences between the current level and the highest level. So it always looks at the highest level when it creates a map.
However, with ZBrush 3 it’s no longer sufficient to simply hide everything except the current UV space. You need to actually split each UV space off into a separate subtool. So after using Tool>Polygroups>Uv Groups you would then use Tool>SubTool>GrpSplit.
Aha… That’s the step I’m missing… interesting. Thank you very much!