Zbrush strange little squares appear on the mesh and cause bake errors, very annoying!

Alex_the3DRookie

Hi, so I was working on a 3D asset for a personal project but found this weird "error" in Zbrush. Little squares appear on the mesh and still remain if I export it to Maya or try to bake the High Poly in Substance Painter. I exported on both FBX and OBJ.
Please forgive if it's something obvious but I have never worked with Zbrush before, I applied some techniques learned from a tutorial and tried my best. The mesh was modeled in Maya with UVs donde, everything re-named correctly and then imported to Zbrush to give the details. I worked in subdivision level of 6.

A friend told me my mistake was probably working in that subdiv level so no idea how that works. I just wondered if I could solve the problem without having to re-do the whole details in Zbrush
Pictures here:







In Maya it's much more apparent:







Thanks for any help, i'm not even a rookie at Zbrush, just wanted to play with it to give the mesh some details.

BagelHero

This is pretty weird and not normal, yeah.
If you don't get any definitive suggestions/replies soon just from description it might help to upload the zpr/ztl/model for folks to poke at honestly...?

Alex_J

i havent opened zbrush in ages, but, i'd try to "clean" the base model. Lower to lowest subdivision level, export as obj, put into your main 3d model app and check normals (do any cleanup if necessary), then import back to zbrush.

you can reproject the details in zbrush so you dont lose work. If you did not do the sculpting on layers though and the funky glitches are part of the sculpt.... well that's your lesson to always work with layers. 

kanga

Did you try and smooth/repair the sculpt in zB?

FourtyNights

It seems your problem is that you have lots of vertical edge loops, but not enough horizontal loops on those meshes. Hence not enough resolution to sculpt details.

You should work on your sculptable bases and add more loops to have a as evenly spaced quad grid as you can do on them before subdividing and detailing.

EDIT: Our polycount member AlecMoody explained this with a nice GIF what kind of sculptable base mesh is the best for ZBrush detailing:

More from his thread here. Basically the props he did for that game are pretty much what you're doing, so great: https://polycount.com/discussion/149124/the-order-1886-art-dump/p1

cryrid

If I had to guess, I'd put my money on the UVs/faces detaching and flipping. But a ztl would help confirm the issue like BagelHero suggested. 

gnoop

I usually do  it this way in Blender  thanks to re-mesher and data transfer  modifiers.     Max can do it too.   Maya probably too

In many cases you don't even have to mess with hi to low poly baking ray distances  or cages.      I bake object space for remeshed .  Then  apply  the very same texture to low poly  and re-bake it into tangent space.