SURF-001 · Free-form Surfaces · difficulty 3/5

Ergonomic mug handle (revolved spline)

sha256:4cb1ee01a07710fa…

§1Prompt verbatim

Coffee-mug handle: ergonomic loop, max outer width 80 mm, inner finger clearance 35 × 25 mm, cross-section a smooth-rounded rectangle 12 × 8 mm with R3 mm fillets on all four corners. G2-continuous everywhere. Single watertight solid.

§2Ground-truth spec

shells1

watertighttrue

manifoldtrue

acceptance ε±0.1 mm

featuresg2_continuous_section

§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

canonical reference

REFERENCE

canonical · ground truth

1.000100✓

Human Baseline (Mech-E)

OpenAI o4 (reasoning) → CadQuery

OpenAI + CadQuery 2.4

OpenAI + CadQuery 2.4

Claude Sonnet 4.6 → CadQuery

Anthropic + CadQuery 2.4

0.46310✗

Claude Opus 4.7 → OpenSCAD

Anthropic + OpenSCAD 2024.06

0.4430✗

Claude Opus 4.7 → CadQuery

Anthropic + CadQuery 2.4

0.40515✗

DeepSeek R1 (reasoning) → CadQuery

DeepSeek + CadQuery 2.4

0.39312✗

Qwen3 Coder → CadQuery

Alibaba + CadQuery 2.4

0.34816✗

Claude Haiku 4.5 → CadQuery

Anthropic + CadQuery 2.4

0.34014✗

CAD-Coder R1

CAD-Coder Labs (research)

0.33818✗

Llama 3.3 70B → OpenSCAD

Meta + OpenSCAD 2024.06

0.30917✗

GPT-5 Mini → OpenSCAD

OpenAI + OpenSCAD 2024.06

0.29819✗

Gemini 2.5 Flash → CadQuery

Google + CadQuery 2.4

0.26419✗

Gemini 2.5 Pro → OpenSCAD

Google + OpenSCAD 2024.06

0.2020✗

DeepCAD

Wu et al. 2021 (research)

0.16731✗

no manifold solid produced

Hunyuan3D-2

Tencent

—5✗

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

Agent	Bidirectional Chamfer	Hausdorff p95	NormCons	Watert.	Manif.	P@1	p50	latency	cost
Human Baseline (Mech-E)	0.114	0.659	0.915	✓	0.966	1.000	—	643.9s	$5.846
Trellis 3D	0.119	0.631	0.893	✓	0.951	0.000	—	11.3s	$0.051
OpenAI o4 (reasoning) → CadQuery	0.149	0.690	0.868	✓	0.945	1.000	—	136.3s	$1.289
Zoo Text-to-CAD	0.129	0.648	0.865	✓	0.942	0.000	—	6.4s	$0.165
Adam (CADcrush)	0.195	0.965	0.807	✓	0.921	0.000	—	9.3s	$0.272
GPT-5 → CadQuery	0.192	1.002	0.784	✓	0.917	0.000	—	52.7s	$0.169
Spline AI	0.201	0.951	0.791	✓	0.920	0.000	—	9.4s	$0.036
Claude Sonnet 4.6 → CadQuery	0.173	0.902	0.790	✓	0.920	0.000	—	21.8s	$0.060
Claude Opus 4.7 → OpenSCAD	0.167	0.841	0.808	✓	0.920	0.000	—	35.2s	$0.325
Claude Opus 4.7 → CadQuery	0.205	1.073	0.784	×	0.912	0.000	—	49.3s	$0.384
DeepSeek R1 (reasoning) → CadQuery	0.205	0.973	0.771	×	0.909	0.000	—	86.9s	$0.046
Qwen3 Coder → CadQuery	0.218	1.195	0.750	×	0.904	0.000	—	23.2s	$0.033
Claude Haiku 4.5 → CadQuery	0.247	1.095	0.755	×	0.902	0.000	—	8.4s	$0.020
CAD-Coder R1	0.253	1.268	0.749	×	0.901	0.000	—	4.9s	$0.006
Llama 3.3 70B → OpenSCAD	0.270	1.311	0.736	×	0.894	0.000	—	18.4s	$0.021
GPT-5 Mini → OpenSCAD	0.289	1.422	0.721	×	0.893	0.000	—	15.9s	$0.009
Gemini 2.5 Flash → CadQuery	0.301	1.375	0.719	×	0.893	0.000	—	12.9s	$0.022
Gemini 2.5 Pro → OpenSCAD	0.397	1.983	0.686	×	0.879	0.000	—	23.5s	$0.090
DeepCAD	0.437	2.231	0.675	×	0.877	0.000	—	5.2s	$0.019
Hunyuan3D-2 kernel error: BRepCheck_NotClosed	—	—	—	×	0.000	0.000	—	33.6s	$0.080