Mesh rebuild freecad bracket
hard tier · create
The request
I've attached an STL of an L-bracket exported from a CAD application. Rebuild it as a clean parametric part: one sub-part named exactly `bracket`, matching the mesh's dimensions, hole positions and slots, and standing in the same place as the mesh (Z up, same origin — build it where the import sits, don't re-centre it). Give it three controls — `width`, `thickness` and `holeDiameter` — whose defaults match the mesh and whose ranges cover ±10 mm, 2–8 mm and 3–8 mm. Keep the mesh imported in the part while you work. Measure the mesh first; do not guess.

What the AI judge checks
- The overall form matches the reference: the same kind of object, the same silhouette from the matching angle
- Proportions match: the relative sizes of the major dimensions agree with the reference within what the eye can judge
- Every major feature visible in the reference (holes, slots, bosses, tabs, lips) is present in the result
- Those features sit where the reference has them
- Nothing is present that the reference does not show — no decorative or unexplained geometry
- Edges are straight and faces are flat — a CAD rebuild, not a copy of the mesh's facets
- The slots are elongated openings, not round holes
Measured checks
- one sub-part named bracket (gate)
- volume within 3 % of the mesh (gate)
- bounding box within 0.5 mm of the mesh (gate)
- symmetric difference under the measured floor
- holes match the mesh
- the imported bracket is still declared as an import
- asked the oracle at most once
Ranked by hand
One reviewer put one attempt from each model in order, best first, ties left tied.
Ordering by hand decides Human rank and Human rate on the leaderboard; it never affects Overall or Strict.
Every model's attempts
Run baseline-2026-092026-09-10commit 41aec7daspend $339.70 + $48.02 AI judging, 7 unpricedOther runs: 2026-09-04T20-02-10-stage2-hard-cases, 2026-09-04T19-48-31-screen-14-fixed