PARA-005 · Paraphrase Robustness · difficulty 4/5

5× paraphrased planetary carrier

sha256:2b97cc4d1ef0aa55…

§1Prompt verbatim

Disc Ø 80 × 8 mm with central Ø 12 H7 bore, three Ø 6 H7 satellite bores on a 30 mm PCD at 0/120/240°, six M3 tapped holes on a 60 mm PCD at 30° offset.

§2Ground-truth spec

shells1

watertighttrue

manifoldtrue

acceptance ε±0.05 mm

Reference geometry is identical to MECH-027; this task evaluates paraphrase variance, not modelling skill.

§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✓

OpenAI o4 (reasoning) → CadQuery

OpenAI + CadQuery 2.4

0.78611✓

Human Baseline (Mech-E)

n=4 senior engineers

0.72110✓

Claude Opus 4.7 → OpenSCAD

Anthropic + OpenSCAD 2024.06

Claude Opus 4.7 → CadQuery

Anthropic + CadQuery 2.4

OpenAI + CadQuery 2.4

0.6179✗

Claude Sonnet 4.6 → CadQuery

Anthropic + CadQuery 2.4

Qwen3 Coder → CadQuery

Alibaba + CadQuery 2.4

0.53713✗

Gemini 2.5 Flash → CadQuery

Google + CadQuery 2.4

0.51213✗

GPT-5 Mini → OpenSCAD

OpenAI + OpenSCAD 2024.06

0.48711✗

Claude Haiku 4.5 → CadQuery

Anthropic + CadQuery 2.4

0.48513✗

DeepSeek R1 (reasoning) → CadQuery

DeepSeek + CadQuery 2.4

0.47714✗

Llama 3.3 70B → OpenSCAD

Meta + OpenSCAD 2024.06

Wu et al. 2021 (research)

0.27919✗

no manifold solid produced

Gemini 2.5 Pro → OpenSCAD

Google + OpenSCAD 2024.06

—18✗

no manifold solid produced

CAD-Coder R1

CAD-Coder Labs (research)

—74✗

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	Watert.	Manif.	Paraphrase IoU σ	Seed σ	P@1	p50	latency	cost
OpenAI o4 (reasoning) → CadQuery	✓	0.961	0.020	0.036	1.000	—	115.0s	$1.214
Human Baseline (Mech-E)	✓	0.962	0.007	0.006	0.000	—	733.0s	$6.526
Claude Opus 4.7 → OpenSCAD	✓	0.949	0.036	0.034	0.000	—	23.4s	$0.337
Adam (CADcrush)	✓	0.947	0.056	0.026	0.000	—	10.5s	$0.229
Claude Opus 4.7 → CadQuery	✓	0.942	0.030	0.049	0.000	—	47.8s	$0.362
Zoo Text-to-CAD	✓	0.950	0.027	0.024	0.000	—	7.2s	$0.149
GPT-5 → CadQuery	✓	0.938	0.043	0.043	0.000	—	48.6s	$0.175
Claude Sonnet 4.6 → CadQuery	✓	0.946	0.030	0.057	0.000	—	20.5s	$0.060
Trellis 3D	✓	0.935	0.051	0.122	0.000	—	12.8s	$0.052
Qwen3 Coder → CadQuery	✓	0.932	0.059	0.054	0.000	—	17.5s	$0.031
Gemini 2.5 Flash → CadQuery	✓	0.925	0.042	0.072	0.000	—	11.6s	$0.017
GPT-5 Mini → OpenSCAD	✓	0.927	0.042	0.068	0.000	—	17.2s	$0.012
Claude Haiku 4.5 → CadQuery	✓	0.925	0.052	0.042	0.000	—	8.0s	$0.019
DeepSeek R1 (reasoning) → CadQuery	✓	0.925	0.040	0.069	0.000	—	74.2s	$0.038
Llama 3.3 70B → OpenSCAD	✓	0.922	0.077	0.045	0.000	—	27.5s	$0.024
Hunyuan3D-2	✓	0.922	0.050	0.074	0.000	—	29.5s	$0.059
Spline AI	✓	0.918	0.068	0.073	0.000	—	8.1s	$0.047
DeepCAD	×	0.895	0.102	0.059	0.000	—	5.1s	$0.022
Gemini 2.5 Pro → OpenSCAD kernel error: BRepCheck_NotClosed	×	0.000	—	—	0.000	—	33.0s	$0.104
CAD-Coder R1 kernel error: BRepCheck_NotClosed	×	0.000	—	—	0.000	—	6.7s	$0.005