How to Fix Broken Lines & Faceted Arcs When Exporting SketchUp to AutoCAD DXF
Why native SketchUp DXF export shatters curves into thousands of segments—and how topological welding, 2-vertex Bulge arc fitting, and Uniform Scale Layer 0 blocks deliver clean CAD drawings.
- Closed loops are topologically welded into 100% continuous LWPOLYLINE entities (<0.01mm gap snap)
- Kåsa circle fitting reconstructs true 2-vertex Bulge CAD arcs ready for native DIMRADIUS dimensioning
- Nested components map cleanly to Layer 0 (ByBlock) with Uniform Scale so EXPLODE never fragments geometry
1. Why Native SketchUp 2D CAD Exports Frustrate Architects
Standard SketchUp 2D DWG/DXF export projects triangulated mesh edges individually, scattering thousands of disconnected LINE primitives while turning smooth curved walls and columns into segmented polygons.
Even worse, non-uniformly scaled groups produce sheared CAD blocks or microscopic slivers (<0.05mm) that break AutoCAD HATCH boundary detection and bloat file sizes.
2. Topological Loop Welding & 6-Guard True Arc Reconstruction
SU·CAD Pro pre-filters sub-0.05mm degenerate noise, builds a directed adjacency graph within 0.1mm tolerance, and welds connected edges into watertight LWPOLYLINE curves.
Curved facades and circular columns are analytically fitted into 2-vertex Bulge arcs, guarded by six geometric invariants (vertex count, chord ratio, obtuse angle bounds) so rectangular structural columns are never misclassified as arcs.
- Reduces DXF vertex count and file size by over 60% on curved architecture
- Automatically flattens non-uniformly sheared assemblies to 1:1 world coordinates
- Preserves full nested Component hierarchy for clean AutoCAD BEDIT editing
3. Three Steps to Zero-Warning AutoCAD Drawings
Step 1: Activate your Plan, Section, or Elevation scene in SketchUp and toggle Live LWT to verify stroke hierarchy.
Step 2: Open 1-Click DXF Export and enable Continuous Polyline Welding + Layer 0 ByBlock Component Reuse.
Step 3: Export—your DXF opens instantaneously in AutoCAD 2000–2026+ with zero errors or audit warnings.
Try SU·CAD Pro v3.88.91 on Your Own SketchUp Model
Zero-config offline .rbz bundle for SketchUp 2017–2026+ on Windows 10/11.