Preprint · cad-bench/v0.5 · sweep 2026-04-12open · MIT
CAD·Benchv0.5
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PARA-001 · Paraphrase Robustness · difficulty 3/5

5× paraphrased L-bracket

sha256:1f3a5e90c44b2210

§1Prompt verbatim

Right-angle L-bracket, leg lengths 60 mm and 40 mm, thickness 5 mm. Through-hole Ø 6.6 mm centred 30 mm from the bend on the long leg.

§2Ground-truth spec

shells1
watertighttrue
manifoldtrue
acceptance ε±0.1 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
AgentWatert.Manif.Paraphrase IoU σSeed σP@1p50latencycost
Human Baseline (Mech-E)0.9730.0060.0031.000870.0s$6.284
Zoo Text-to-CAD0.9660.0350.0220.0004.6s$0.207
Claude Opus 4.7 → CadQuery0.9600.0210.0390.00036.8s$0.323
Gemini 2.5 Pro → OpenSCAD0.9450.0360.0490.00031.6s$0.103
GPT-5 → CadQuery0.9480.0370.0540.00035.4s$0.191
Adam (CADcrush)0.9320.0430.0230.00012.2s$0.244
Trellis 3D0.9340.0600.0770.0009.6s$0.043
Claude Opus 4.7 → OpenSCAD0.9300.0460.0450.00037.0s$0.263
Spline AI×0.9100.0630.0960.00010.2s$0.045
DeepCAD×0.9080.0820.0450.0003.9s$0.021