OpenCASCADE (OCCT)MCADConfidence: Medium

Boolean operations on two valid lofts sharing an end section return impossible results with no error: Fuse(body, lip) comes back empty and Common is zero on both OCCT 7.9.3 and 8.0.1, and on 8.0.1 Cut is larger than its object, all with IsDone() true. Reproduced on OCCT 7.9.3 and 8.0.1 with measured volumes against a point-classification ground truth; argument order flips the outcome. The reporter traced it to a real F1 airbox model where the same pair lost the body.

Impact Analysis

Persona

Mechanical Designer

Team Size Impact

5x Multiplier

Prototype Delay

2 Days

Est. Annual Cost

$12,000

1 user · 1 month180 min
Rest of team720 min
Rest of year9,900 min

monthly_minutes × 12 × team_multiplier ÷ 60 × $75/hr = $12k/yr

$75/hr assumed rate.

Annual team-minutes decomposed from the reported monthly inputs.

Evidence & Sources

1 Sources

Open-Cascade-SAS/OCCT issue #1643: Booleans on two valid lofts that share an end section: Fuse empty, Common zero, Cut larger than its object

github.com

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Analyst Notes

From the Grok ProductFlo pain-radar digest, Oct 19 2026. Verified live 2026-10-19: full issue read with measured volume tables on both OCCT versions; BRepAlgoAPI_Check passes on the inputs. Cost model assumes an engineer debugs phantom geometry downstream.