Pushback tractor

Note: Size: the body is 5.6 m long, 2.5 m wide and 1.25 m tall at the deck. The tow hitches bring the overall length to 6.44 m, the cab step makes it 2.67 m across, and the top of the beacon is at 2.52 m (cab roof at 2.3 m). The tyres are 1.0 m across on a 3.5 m wheelbase. The origin is at the bottom centre, all four tyres rest on y = 0, the front (cab windscreen and wiper) faces +Z and the cab sits on the left (+X) side. The GLB has 1,300 triangles in 38 meshes. Every material is named exactly after a kit palette colour; 10 of the 12 are used (navy light and dark wood are not). The exporter writes one material per mesh, so the same colour name appears on several materials: recolour by name. The baked clip scene-motion (6 s, seamless) moves only parts on their own pivots. All four wheels roll 1 whole turn on their axles. Each wheel sits in a kingpin node that swivels about a vertical axis through the wheel centre, with the rear pair steering opposite to the front for a coordinated turn. The wiper sweeps twice about its spindle, normal to the windscreen. The beacon head makes 6 turns on its base. The body never moves. The glazing is an opaque navy-dark panel with no cab interior. The tyres have 16 facets, so while they roll the contact point rises and falls by about 5 mm. Params are baked into the GLB at their defaults and only change the model when the scene is rebuilt in the viewer. airlineLivery (the kit's 'Airline livery') sets the height of the navy band along the body sides (3 to 17 cm) and around the cab (3 to 23 cm). steerAngle sets the steering amplitude of the loop; its 0.2 rad maximum keeps the swivelled tyres inside the arches. cabHeight raises the cab roof and the beacon. Only the default params were rendered and checked; the extremes were not captured. glb-lint: 0 errors and 7 heuristic warnings. Two come from the per-mesh materials (material count and duplicates). One flags non-indexed geometry, which is deliberate flat shading. One flags overlaps where the chassis core, cab glazing and pillars are deliberately nested. One flags parts as 'detached' because each part's meshes sit in their own group, though all of them rest on the body. One flags the 2.5 m height against a generic 1 m reference. One reports the model dipping 0.19 m below the ground, but that comes from the lint's box around the rotated tyre bounds in the exported mid-roll pose. Measured against the actual vertices, the lowest point is -0.005 m (a tyre facet mid-roll). The verdict reads UNVERIFIED only because no host requirements contract was supplied. plan-check passes except for its part-id regex, which rejects the hyphens in the slug-based ids this library requires. With the ids substituted it passes. three-check accepts the real ids, and all 21 survive the GLB reload.