ZBrush Tip: Auto Groups: Convert Disconnected Shells into Polygroups

Rapidly organize complex meshes by converting every disconnected shell into its own PolyGroup with Auto Groups. It’s the quickest path from messy imports to clean selections, targeted edits, and production-ready splits.

When to use

• After importing kitbash or CAD meshes with multiple loose parts.
• Post-Boolean or Dynamesh operations to regain clean selection control.
• Before ZRemesher with Keep Groups, to preserve borders and define flow.
• When preparing SubTool splits for UVs, baking, or animation handoff.

How to do it

1. Turn on PolyFrame (Shift+F) to visualize current Polygroups and topology.
2. Ensure only the relevant geometry is visible (Ctrl+Shift to hide/show as needed).
3. Go to Tool > Polygroups > Auto Groups to assign a unique PolyGroup to each disconnected island.
4. If your mesh has reliable UVs, try Tool > Polygroups > Auto Groups With UV to split by UV islands.
5. Optionally convert groups to separate SubTools: Tool > SubTool > Split > Groups Split.

Power combos

• ZRemesher + Keep Groups: Maintain crisp borders across parts; adjust Smooth Groups for edge fidelity.
• Group Loops: Add supporting loops around PolyGroup borders for hard-surface control before subdivision.
• Move Topological: Edit one island at a time without affecting neighbors; perfect for quick part tweaks.
• Visibility by Group: Ctrl+Shift-click a group to isolate; Ctrl+Shift+drag empty canvas to invert visibility.

Troubleshooting

• If everything becomes one group, the mesh is truly welded. Use Tool > Geometry > Mesh Integrity > Check Mesh, then Fix Mesh; also try Modify Topology > WeldPoints (or adjust import Weld settings) to address stray vertices and gaps.
• Tiny, unwanted islands? Use Select Lasso to hide them, then Geometry > Modify Topology > Delete Hidden. Alternatively, Close Holes to consolidate surfaces before regrouping.
• Overlapping UVs can confuse Auto Groups With UV. Unwrap cleanly with UV Master (preserve Polygroups) and retry.

Workflow accelerators

• Assign a hotkey: Ctrl+Alt+click Auto Groups, press a key to bind.
• Refine selections with Group Masked (Ctrl+W on a mask) and Group Visible to consolidate targeted areas.
• Speed up part management by pairing Auto Groups with Groups Split, then rename SubTools for clarity.
• Leverage Polygroups as selection sets in posing, deformation, and baking workflows.

Pipeline note

• Many DCCs can interpret Polygroups as selection sets or material IDs via FBX/OBJ. Enable the corresponding options during export to streamline downstream texturing and rigging.

Need licenses, upgrades, or expert guidance? Explore ZBrush solutions at NOVEDGE, and browse ZBrush-related offerings and add-ons via NOVEDGE’s ZBrush search. Their team can help tailor the right setup for your studio pipeline.