PARAM-013 · Constraint Solving & Editability · difficulty 4/5

Editable bracket (length+30 %, hole→M8)

sha256:fab07d2c5e914421…

§1Prompt verbatim

Build the L-bracket from MECH-014, then perform two parametric edits in sequence: (1) increase the long leg from 60 → 78 mm; (2) change the through-hole from M6 clearance to M8 clearance (Ø 9.0 mm). Topology must remain valid throughout.

§2Ground-truth spec

shells1

watertighttrue

manifoldtrue

acceptance ε±0.1 mm

parametric edits

leg_long : 60 → 78 (ΔV expected 3600 mm³)

hole_d : 6.6 → 9 (ΔV expected -147 mm³)

§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

0.7428✓

Claude Opus 4.7 → CadQuery

Anthropic + CadQuery 2.4

0.6579✓

GPT-5 → CadQuery

OpenAI + CadQuery 2.4

Gemini 2.5 Pro → OpenSCAD

Google + OpenSCAD 2024.06

0.4530✗

DeepCAD

Wu et al. 2021 (research)

0.12940✗

no manifold solid produced

Claude Opus 4.7 → OpenSCAD

Anthropic + OpenSCAD 2024.06

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.	ParamEdit	ConSolve	Parametric Range Integrity	p50	latency	cost
Human Baseline (Mech-E)	✓	0.969	0.831	0.870	0.812	—	847.1s	$4.885
Claude Opus 4.7 → CadQuery	✓	0.953	0.802	0.846	0.765	—	32.2s	$0.320
GPT-5 → CadQuery	✓	0.932	0.693	0.699	0.701	—	50.1s	$0.194
Adam (CADcrush)	✓	0.943	0.797	0.693	0.746	—	7.6s	$0.306
Zoo Text-to-CAD	✓	0.937	0.661	0.734	0.651	—	7.7s	$0.192
Gemini 2.5 Pro → OpenSCAD	✓	0.922	0.551	0.570	0.471	—	24.2s	$0.105
DeepCAD	×	0.870	0.281	0.302	0.232	—	6.1s	$0.024
Claude Opus 4.7 → OpenSCAD kernel error: BRepCheck_NotClosed	×	0.000	—	—	—	—	33.7s	$0.308
Trellis 3D	×	0.850	0.058	0.059	0.037	—	8.5s	$0.047
Spline AI	×	0.850	0.048	0.049	0.018	—	9.2s	$0.047