ZBrushCentral

Critical Zbrush Duplication Bug

ZBrush Usage Questions
#1

I came across an awful bug today in ZBrush 2018 that can corrupt a file or hard crash ZBrush if you aren’t careful. Very simple to replicate.

  1. Swap to polymesh3D or any mesh3d subtool.
  2. Subdivide subtool once or twice (tends to be worse with more subdivisions).
  3. Switch to Move tool with gizmo.
  4. Ctrl+move to duplicate the mesh.
  5. Rotate the view and you might notice odd draw behavior.
  6. Step up and down subdivisions and the mesh will explode or ZBrush may crash.
  7. Swap to a different subtool and/or scroll a long list of subtools that include the bugged subtool and you'll crash.

It’s very consistent, and the scary part is if you leave a subtool like this in your list and save the file you won’t be able to use the file when you reopen it or even a project it was in (since it crashes on trying to draw I think). The error that sometimes displays seems to be a memory error so perhaps this is a leak or maybe something more serious.

Just wanted to let you know about this since I almost lost a few hours progress but fortunately had an non-corrupted quick-save.

#2

If you are going to duplicate a subtool in that manner with multiple subdivision levels, then enable “Freeze SubDivision Levels” first before you duplicate it.

#3

Thanks that seems to work! But you really shouldn’t be able to modify topology like that on the highest subdiv in the first place since every other tool seems to prohibit it in ZBrush (Mirror and Weld for example and many others). It can destroy a project or ztool file if someone isn’t careful (since even selecting the subtool with the error causes a crash). Is there a specific sub forum for bug reports or is the best place to put it?

#4

I’ve notified the development team of this problem.

#5

Another alternative to freezing is to duplicate at the highest levels, and Del Lower (either before or after the duplication). You can then reconstruct the lower subdivision levels as needed. This method eliminates the error while preserving all the sculpted details (freezing basically gives you the result of raw subdivision only on the duplicated base geometry).

I do agree that this feature should be disabled when subdivision levels (and layers, etc) are present since it changes the number of vertices and the existing subdivision levels don’t know how to compensate with this mismatch.