Preprint · cad-bench/v0.5 · sweep 2026-04-12open · MIT
CAD·Benchv0.5
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SKETCH-003 · 2-D Sketch Constraints · difficulty 2/5

Tangent-arc transition profile

sha256:12aa30c87ef00921

§1Prompt verbatim

Closed profile: horizontal segment 50 mm, tangent-arc R 20 mm sweeping 90°, vertical segment 50 mm, tangent-arc R 20 mm sweeping 90° back to start. Apply tangent + equal-length + perpendicular constraints. Sketch must be fully constrained (DOF = 0).

§2Ground-truth spec

acceptance ε±0.001 mm

§3Reference render

canonical reference · drag to orbit, scroll to zoom

Visualisation is rebuilt in-browser from the canonical parametric description. Scoring is performed against the held-out reference STEP file (sha-256 fingerprint above).

§4Per-agent renders

reference + 10 agent outputs · scored against the held-out STEP
vol IoU · BREP · manifold

Each tile is rebuilt from the canonical parametric description and degraded to match the agent's scored profile (tessellation, non-manifold face removal, dimension scale jitter, missing features). Image-only diffusion models render visually plausible meshes but score in the single digits on BREP fidelity — the geometry is not a manifold solid even when the render reads clean.

§5Per-agent metrics

ranked by Vol IoU · same data as the leaderboard, restricted to this task
AgentBidirectional ChamferWatert.Manif.ConSolveP@1p50latencycost
Claude Opus 4.7 → CadQuery0.1150.9670.7531.00029.1s$0.346
Human Baseline (Mech-E)0.1220.9720.8130.000901.1s$5.536
Adam (CADcrush)0.1360.9570.6920.0007.0s$0.246
Gemini 2.5 Pro → OpenSCAD0.1550.9530.5280.00020.1s$0.087
Zoo Text-to-CAD0.1300.9510.7400.0007.2s$0.182
GPT-5 → CadQuery0.1390.9480.7450.00048.7s$0.169
Claude Opus 4.7 → OpenSCAD0.1570.9360.6060.00023.9s$0.371
DeepCAD0.475×0.8760.3120.0004.4s$0.021
Trellis 3D1.610×0.8560.0570.00014.6s$0.040
Spline AI1.607×0.8500.0450.0005.9s$0.046