Aero QA Geometry

Geometry QA

Read docs/guidebook/01-openvsp.md and execute its "Check your work" list.

Non-negotiables for this repo:

• OpenVSP setters fail silently: any new SetParmVal needs read-back coverage in build_openvsp_model's verification block, and errors must be drained via vsp.ErrorMgrSingleton.getInstance() (module-level error functions do not exist).
• Read-back proves values, never choices: a wrong rotation axis reads back "correctly" while the exported mesh is garbage (audit F14). The stage ok therefore requires readback.matches_spec, stl_bbox.ok, AND mesh_checks.ok (per-component extents, fin verticality, attachment, computed whole-model height — all measured from the exported STL).
• Always open threeview.png: it is rendered from the exported mesh, not the spec. If you change the builder, look at it before trusting any number.
• Set wing driver groups before planform parms; pin Sweep_Location to 0 for LE sweep; Update() before any read-back or export.
• A wing.sections reproduction needs one driver group per panel, exact per-section read-back, and a reopened-VSP3 check. OpenVSP 3.51 retains a stale aggregate area after XSec insertion unless TotalSpan is nudged and restored; without that recomputation the saved wing rescales on reopen. Require geometry.json .wing.planform_mode == "sections", .openvsp.readback.wing_sections.matches, and the true section polygon in .planform.planform_xy.
• MassProp Total_Mass is unitless volume-proxy unless densities were set — never quote it as kilograms.
• Fin roots: geometry.json .openvsp.fin_attach.mode must match vtail.root_attachment. In measured mode the selected y/z must equal the spec exactly and read-back must verify both mirrored fins. If the visible root is outside the core body, require a source-measured fuselage.fairings loft plus derived vtail*_root extensions: actual-transform fairings_match, vtail_root_extensions_match, zero signed extension-tip junction gap, buried LE/mid/TE eccentricities ≤0.8, fin_*_attached, and fairing_*_contained (≥95% at least 2 mm inside the independent body/wing solids) must all pass after VSP3 reopen. The attachment verdict uses the authoritative body/fairing section at root x and a 10 mm or 0.2%-length proximity floor; never restore the old ±0.12 m bounding slab / 60 mm floor. Extensions are reproduction-only. Fairings and root extensions are loft-only and must be absent from VSPAERO lifting sets.
• Packing: payload bay must clear the engine compartment front (L - 0.20 - engine_length - 0.05) and fuel volume must fit wing tanks + fuselage leftover (packing_report).
• Reference model (guidebook chapter 13): when designs/<concept>/reference/reference.json exists, geometry.json carries reference_fidelity (gating: body p95 surface deviation and top/side silhouette IoU; disclosed: whole-aircraft and wing/fin p95, station and planform deltas; reference_sha256) and the phase directory holds reference_overlay.png. For sketch.treatment: reproduction the stage ok and the Geometry-truth gate require reference_fidelity.ok; otherwise it is disclosed evidence. Open the overlay. Any departure must trace to a documented unrepresentable feature in the brief, never to measurement error. For a sectioned wing, the disclosed exposed-wing p95 is model-to-reference outside the scan-derived body exclusion; pair it with silhouette reference-only area so omitted geometry cannot hide. Retain full component p95 as buried carry-through disclosure. The reference is measured design input — not validation truth.