SKETCH-014 · 2-D Sketch Constraints · difficulty 2/5

Symmetric four-bar profile

sha256:4ec01fde2cb0a911…

§1Prompt verbatim

Closed planar profile, mirror-symmetric about the Y axis: two horizontal segments 80 mm long at y = 0 and y = 40, joined by two semicircular arcs R 20 mm. Constraints: horizontal+horizontal, equal-length, tangent at every endpoint, mirror symmetry. 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

canonical reference

REFERENCE

canonical · ground truth

1.000100✓

Human Baseline (Mech-E)

n=4 senior engineers

0.88910✓

Claude Opus 4.7 → CadQuery

Anthropic + CadQuery 2.4

0.7628✓

Claude Sonnet 4.6 → CadQuery

Anthropic + CadQuery 2.4

DeepSeek R1 (reasoning) → CadQuery

DeepSeek + CadQuery 2.4

0.6468✗

OpenAI o4 (reasoning) → CadQuery

OpenAI + CadQuery 2.4

0.6269✗

GPT-5 → CadQuery

OpenAI + CadQuery 2.4

0.6178✗

Gemini 2.5 Pro → OpenSCAD

Google + OpenSCAD 2024.06

0.6100✗

CAD-Coder R1

CAD-Coder Labs (research)

0.59911✗

Claude Opus 4.7 → OpenSCAD

Anthropic + OpenSCAD 2024.06

0.5790✗

Gemini 2.5 Flash → CadQuery

Google + CadQuery 2.4

Claude Haiku 4.5 → CadQuery

Anthropic + CadQuery 2.4

0.50811✗

GPT-5 Mini → OpenSCAD

OpenAI + OpenSCAD 2024.06

0.50612✗

Qwen3 Coder → CadQuery

Alibaba + CadQuery 2.4

0.47610✗

Llama 3.3 70B → OpenSCAD

Meta + OpenSCAD 2024.06

0.40415✗

DeepCAD

Wu et al. 2021 (research)

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	Watert.	Manif.	ConSolve	P@1	p50	latency	cost
Human Baseline (Mech-E)	0.105	✓	0.978	0.809	1.000	—	911.3s	$6.652
Claude Opus 4.7 → CadQuery	0.110	✓	0.958	0.856	1.000	—	49.2s	$0.343
Claude Sonnet 4.6 → CadQuery	0.114	✓	0.968	0.780	0.000	—	13.7s	$0.057
Zoo Text-to-CAD	0.109	✓	0.967	0.693	0.000	—	5.1s	$0.166
DeepSeek R1 (reasoning) → CadQuery	0.132	✓	0.949	0.803	0.000	—	98.5s	$0.043
OpenAI o4 (reasoning) → CadQuery	0.134	✓	0.940	0.855	0.000	—	83.8s	$1.191
GPT-5 → CadQuery	0.148	✓	0.945	0.781	0.000	—	32.2s	$0.181
Gemini 2.5 Pro → OpenSCAD	0.125	✓	0.944	0.532	0.000	—	26.8s	$0.091
CAD-Coder R1	0.122	✓	0.945	0.618	0.000	—	7.2s	$0.005
Claude Opus 4.7 → OpenSCAD	0.163	✓	0.932	0.657	0.000	—	34.5s	$0.279
Gemini 2.5 Flash → CadQuery	0.134	✓	0.943	0.589	0.000	—	14.9s	$0.017
Adam (CADcrush)	0.147	✓	0.940	0.745	0.000	—	6.8s	$0.236
Claude Haiku 4.5 → CadQuery	0.190	✓	0.926	0.508	0.000	—	6.3s	$0.018
GPT-5 Mini → OpenSCAD	0.156	✓	0.929	0.433	0.000	—	12.5s	$0.008
Qwen3 Coder → CadQuery	0.169	✓	0.920	0.654	0.000	—	14.6s	$0.027
Llama 3.3 70B → OpenSCAD	0.227	×	0.907	0.396	0.000	—	16.5s	$0.020
DeepCAD	0.284	×	0.895	0.310	0.000	—	4.6s	$0.019
Trellis 3D	1.640	×	0.853	0.060	0.000	—	14.2s	$0.052
Spline AI	1.631	×	0.852	0.050	0.000	—	7.1s	$0.044
Hunyuan3D-2 kernel error: BRepCheck_NotClosed	—	×	0.000	—	0.000	—	37.0s	$0.073