Fire engine

Note: Size: a cab-forward aerial pumper 8.52 m long from the front bumper to the rear step, 2.54 m wide across the body (3.02 m over the mirrors) and 3.61 m tall to the top of the ladder at rest (cab roof 2.85 m, body roof 2.45 m). The ladder tip rises to about 4.9 m at the top of its lift. Tyres are 1.0 m across on a 4.5 m wheelbase, with dual tyres at the rear. The origin is at the bottom centre of the footprint, the tyres rest on y = 0, and the cab front faces +Z. The GLB has 4,216 triangles in 67 meshes, merged per part and per colour. Every material is named exactly after a kit palette colour. 8 of the 12 are used (brick, brick dark, brick light and dark wood belong to the station buildings). The exporter writes one material per mesh, so the same name repeats: recolour by name. The baked clip scene-motion (6 s, seamless) moves only parts on their own pivots. The wheels roll 1 whole turn. The front wheels sit in kingpin nodes that swivel ±0.1 rad. The turntable swings ±8° about vertical. The ladder lifts from its 4° rest about its heel pin (ladderLift above rest, never below). The ram barrel swivels on its foot pin while its rod slides, so the rod end stays on the ladder's ram eye. The bell rocks twice on its yoke axle. The beacons make 6 turns. The body never moves. Windows are opaque panels with no interior. Params are baked into the GLB at their defaults and only change the model when the viewer rebuilds the scene. engineLivery (the kit's 'Engine livery') widens the white bands on the cab and body from pinstripes (0) to broad bands (1); from 0.8 up the cab roof turns white too. ladderLength sets the aerial ladder from 4.5 to 7 m. ladderLift sets the lift amplitude in the loop (0 holds it at rest). compartments sets 2–4 roller doors ahead of the rear wheels on each side. Only the default params were rendered and checked; the extremes were not captured. glb-lint: 0 errors and 6 heuristic warnings (material count and duplicates from the per-mesh exporter, non-indexed flat-shaded geometry, deliberate trim overlaps, parts flagged 'detached' because each sits in its own group, and height against a generic 1 m reference). Its bounds y range of -0.19 to 4.61 is computed from rotated mesh boxes in the exported mid-loop pose (tyres mid-roll, ladder lifted), not from the actual vertices. 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 26 survive the GLB reload. Two earlier three-check runs had one page-load timeout each because the machine was heavily loaded; the final full run passed 24 of 24 checks.