ZBrushCentral

Create Shell doesn't give me new polygroup for interior shell

ZBrush Usage Questions
#1

I’m having an issue with the Dynamesh create shell function… I’ve followed the Ask ZBrush YouTube video and everything works according to the advice in that video, except my newly created interior shell has the same polygroup rather than a different one 0_0 I’m using ZBrush 2020 and doing the following steps…

  1. Dynamesh my subtool
  2. Appending a cylinder and positioning it so it penetrates my subtool
  3. Changing cylinder subtool to a subtractive tool
  4. Clicking merge down from original subtool so both original tool and cylinder are now one subtool’
  5. Turn on show polygroups and confirming original subtool and cyclinder are different polygroups.
  6. Click create shell
  7. Final result is a correctly hollowed out subtool but the whole thing is one polygroup.

Any help greatly appreciated! Cheers

#2

Hi @WickedResin

Are you certain that they are two different polygroups? They may simply have very similar color coding.

Shift-ctrl click on the interior surface. If everything else but that surface disappears, then it is a separate group. Shift-ctrl click again in empty canvas to un-hide everything.

Otherwise, I don’t know what has happened here–performing this operation by alt-inserting a cylinder with an IMM brush produces separate polygroups for me. The Polygroups > Groups By Normals may fix it with the correct tolerance setting. Failing that, Polygroupit should work with a bit of manual effort.

#3

Hey @Spyndel,

Yep it was definitely the same polygroup on the whole model, though I did manage to find a solution… For anybody else that runs into this issue, what fixed it for me was clicking the “Make Polymesh” button prior to the abovementioned steps.

It still doesn’t make sense to my mind as the original subtool was a sculpted subdivided and then dynameshed tool already! I’d been working on it for several days, hence, it should have already been a polymesh to my understanding… Oh well… The fix was making my already polymeshed tool a polymeshed tool. 0_0