Rhino 3D Tip: Purge exact duplicate geometry with SelDup + Delete

Quickly purge accidental duplicate geometry with Rhino’s SelDup + Delete combo to reduce file size, prevent boolean and join failures, and keep viewports responsive. If you’re new to Rhino or optimizing a seasoned workflow, this is a small habit with an outsized payoff. If you need Rhino licenses or upgrades, check out NOVEDGE for competitive pricing and expert guidance.

• What SelDup finds: exact stacked clones of curves, surfaces, polysurfaces, meshes, annotations, and blocks located in the same position.
• Typical causes: repeated Paste, Array copies left behind, imported DWG/DXF with stacked entities, exploded blocks, Make2D overlaps, and careless dupes during edits.
• Why it matters: duplicates inflate file size, slow selections and redraw, create z-fighting in shaded modes, and cause Booleans/Join/Make2D to fail or misbehave.

Core workflow

• In a heavy scene: switch the active viewport to Wireframe for faster feedback.
• Narrow the scope:
  • Use the Selection Filter panel to limit to Curves, Surfaces, Meshes, or Annotations.
  • Optionally isolate target layers first to avoid touching reference geometry.
• Run SelDup. Rhino will select exact duplicates on visible, unlocked layers.
• Press Delete.

Pro moves

• Make it a one-click macro:
  • Toolbar button or alias macro: _SelDup _Delete
  • Name it “CleanDuplicates” and hit it before saves, exports, or Booleans.
• Clean per type:
  • Turn off all Selection Filters except Curves to prep for Join or Make2D.
  • Switch to Mesh only when optimizing for rendering/3D print exports.
• Post-import hygiene:
  • After DWG/DXF/STEP imports, run SelDup immediately; many CAD exports stack lines and faces.
  • For Make2D results, run SelDup to remove overlapping silhouettes and hidden-line remnants.
• Layer-aware cleanup:
  • Freeze/Lock reference or survey layers first to avoid deleting intentional duplicates.
  • Use Layer States to return to your normal visibility setup after the cleanup.

Diagnostics and safety

• Count feedback: watch the command line to see how many objects were found; repeated high counts indicate a systemic import or workflow issue to fix.
• Not found ≠ not duplicated: SelDup only catches exact coincidences. Near-duplicates may require inspection tools (Distance, Deviation) or Grasshopper culling in complex cases.
• Blocks: consider cleaning within block definitions if duplicates originated there, then update instances.
• Undo-friendly: a quick Ctrl+Z brings back anything removed unintentionally.

Result: lighter files, cleaner intersections, fewer failures, and faster viewports—all in seconds. Need help standardizing team toolbars and macros, or looking to equip your studio with Rhino? Connect with NOVEDGE—their specialists can tailor the best Rhino setup for your workflow.

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