You must be missing a step then, because I just did it with your mesh. 
I will send you back the .ztl
note to anyone reading this thread.
I started completely in ZBrush, I didn’t bring a mesh in from any other app. These are the steps that got me to a model that can’t export a decent displacment map.
- create zSpheres base
- convert to polymesh
- subdivide to 5
- days, days, days of sculpting
- try to export to Max
- find out base model has loads of pinched spots and is basically a mess!
How did ZBrush do this?? I didn’t do anything strange? I just worked inside ZBrush … anyways lessoned learned. I would never start off using ZSpheres, I would create my base mesh in max and import. Apparently that’s the best way.
So be warned! :mad: :mad: :mad: :mad: :mad: :mad: :mad: :mad: :mad:
It really depends on how complicated your zsphere mesh is, and what you do with it. If you move around zpsheres after sculpting. Or sub divide only specific parts after sculpting. Or one of your zspheres was off axis a bit and thus created overlapping geo, that you never noticed because you were way up at level 5 and never looked at it, at level 1 or 2. Then yeah you might get caught with this kind of thing.
My world of war craft zombie that is in my footer was made 100% inside zbrush. using zspheres, and I was (a long with a lot of other people that use zpsheres) able to create a displacement map to use inside of max and have it work just fine. There were spots on it that didn’t hold up very well when i went to max however because of some of the same issues that you had. my fingers for example did some of the same problems that you had, because the placement of the initial zspheres were not optimal and caused some overlapping geo.
In short, yes using a base mesh will yield much better results usually for many many reasons but you can get a zsphere mesh to work with displacement maps just fine, you just gotta be careful 