Rhino 3D Tip: CurveBoolean: Rapidly Convert Overlapping Curves into Closed Extrusion‑Ready Profiles

Use CurveBoolean to convert messy overlaps into clean, extrusion-ready profiles in seconds.

When to reach for CurveBoolean

• Combining overlapping plan-view sketches into a single profile for ExtrudeCrv, Revolve, or Sweep.
• Cleaning imported DWG/DXF linework with duplicates, gaps, and overlaps.
• Preparing logo/text outlines (from TextObject or imported vectors) for manufacturing or rendering.
• Rapidly iterating cutouts, pockets, and perforations in 2D before turning them into 3D features.

Set up for success

• Keep curves coplanar: set your CPlane and, if needed, use ProjectToCPlane to flatten inputs.
• Mind tolerances: File > Properties > Units > Absolute tolerance should match your target precision (e.g., 0.001–0.01 for product work).
• Preflight your curves: ShowEdges/ShowEnds to reveal open ends; Join where appropriate; SimplifyCrv to reduce needless segments.
• Reduce duplicates: SelDup and Delete to avoid ambiguous regions.

Fast workflow

1. Select the overlapping curves and run CurveBoolean.
2. Click inside the regions you want to keep. Each click previews the resulting boundary.
3. Use the command line options to:
   • Delete or keep input curves after creation.
   • Combine multiple picked regions into a single closed boundary or keep them separate.
4. Press Enter to finalize. You’ll get clean, closed profiles ready for downstream operations.

Troubleshooting and power tips

• No selectable region? Look for tiny gaps. Use Extend, CloseCrv, or Match to close them, or Increase tolerance cautiously.
• Strange slivers? Run SelShortCrv and delete or rebuild micro-segments that create narrow regions.
• Too many nodes? Rebuild or SimplifyCrv before CurveBoolean for cleaner outputs and lighter files.
• Keep source curves when exploring options; duplicate your sketch (Copy) and run CurveBoolean on the copy.
• Use Boundary when you need a quick closed edge from surrounding geometry without altering inputs.

Production-ready follow-ups

• ExtrudeCrv or Offset to create solids or layered laminations.
• Hatch regions for drawings; Make2D for documentation with tidy outlines.
• Apply Fillet/Chamfer on curves pre-extrusion to control edge detail consistently.

Pro modeling habits

• Model at real-world scale and set tolerances early to avoid boolean failures later.
• Organize inputs on Layers (e.g., “Sketch”, “Keep”, “Output”) to quickly isolate, lock, or purge.
• Use NamedSelections to store critical curve sets you might revisit.

Why this matters

• CurveBoolean converts manual Trim/Split/Join steps into a single, visual pick workflow.
• Cleaner profiles produce more robust surfaces/solids and reduce downstream rework.
• It accelerates iteration—click different combinations to explore alternatives, then commit.

For Rhino licenses, plugins, and expert advice, check out NOVEDGE. Explore Rhino solutions, training, and add‑ons curated by NOVEDGE to integrate CurveBoolean into a faster, cleaner 2D‑to‑3D workflow.

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