Auto-Zoning and Verification

This chapter covers the AI-assisted Auto-Zoning shortcut for tubular geometries, how to verify your zone setup, and how to troubleshoot common painting and zoning problems.

Auto-Zoning (AI-Assisted)

For tubular geometries, LeaRes can detect inlets and outlets for you.

Step 1: Run Auto-Zoning

1. Open Zoning tools in the viewer toolbar and click Auto-Zoning (“Auto-assign zones using AI (skeleton + SEGNN)”)
2. LeaRes voxelises the surface, extracts its 3D skeleton, and classifies the endpoints with a SEGNN model
3. Zones are created and saved: zone 0 is the inlet, zones 1..N the outlets. The page reloads to render them from the database.

Auto-Zoning creates zones, not boundaries. You still have to create each boundary and assign its type by hand.

Step 2: Create the Boundaries

For each zone Auto-Zoning produced:

1. Click + on the Boundaries container
2. Pick the zone in Associated zone
3. Assign the Boundary type and its parameters

Verify that zone 0 really is the inlet and that the outlets sit at the correct openings; repaint manually if anything is misplaced.

Tip: Auto-Zoning is the fastest way to set up a vascular or airway model. Manual painting remains useful for geometries with unusual openings or when you need precise control.

Verification

Before moving on, confirm:

• Every intended opening has a painted zone
• Every zone is attached to a boundary via Associated zone
• Each boundary has a Boundary type assigned, with its parameters filled in
• The remaining surface (left unpainted) correctly represents wall

Troubleshooting

Painting Does Nothing

Problem: ALT+clicking on the canvas does not paint cells.

Solutions:

• Make sure you have first created a zone with Add new zone (Alt+A) — painting targets the active zone, not a boundary
• Hold ALT while clicking, not just clicking
• Confirm the geometry is loaded and visible in the viewer

Wrong Cells Painted

Problem: The zone extends onto the wall surface instead of just the opening.

Solutions:

• Rotate the view so the opening faces you before painting
• Paint in smaller increments, checking the highlighted cells as you go
• If needed, remove the boundary and add a fresh one to start over

Auto-Zoning Misses an Opening

Problem: Auto-Zoning did not create the expected inlet or outlet.

Solutions:

• Add the missing boundary manually and paint it
• Auto-Zoning works best on clean tubular surfaces; very irregular geometry may need manual zoning

Next Steps

With your zones defined, you’re ready to assign a fluid material to the domain. Continue to Assigning Materials.