School bus

Note: Size: 10.0 m long bumper to bumper, 2.44 m wide across the body (3.0 m across the mirrors) and 3.02 m tall to the roof hatches. The wheels are 1.0 m across. The origin is at the bottom centre, every tyre rests on y = 0 and the front faces +Z. The GLB has 2,256 triangles in 27 meshes. The Suburban Street palette has no yellow, so this is not a yellow bus. The body is painted with a kit colour, and the bus reads as a school bus from its long-nose shape, its black rub rails, its stop arm and its crossing arm. Every material is named exactly after its palette colour. The exporter writes one material per mesh, so the same colour name appears on several materials: recolour by name. Warm white is mildly emissive so the lamps look lit. The baked clip scene-motion (6 s, seamless) moves only parts on their own pivots. The wheels pull away, roll 2 whole turns and brake to a stop, with the speed following sin⁴ so the bus is parked at the loop seam. While it is parked, the stop arm swings out 90° on its vertical hinge behind the driver window (+X side), and the crossing arm swings forward from the curb-side bumper corner (−X side). Both fold back before the bus moves. The body never moves. The tyres have 12 facets, so while they roll the contact point rises and falls by up to about 17 mm. The export snapshots a mid-loop frame, so the glTF's static node pose is a frame from the clip, not t = 0. Because the wheel nodes are slightly rotated in that frame, glb-lint's box-corner bounds read y −0.010, but no vertex goes below y = 0. Play the clip, or seek it to 0, for the rest pose. Params are baked into the GLB at their defaults and only change the model when the scene is rebuilt in the viewer. houseColours (the kit's 'House colours') picks the body paint from light to deep: warm white, lawn green light, lawn green (the default) or lawn green dark. length (8.5–11.5 m) stretches the passenger box, moves the rear axle, and sets the window count. armSwing scales how far the stop arm and crossing arm open in the loop. The extremes were rendered and passed three-check: an 8.5 m warm-white bus with its arms still, and an 11.5 m lawn-green-dark bus with full swing. glb-lint: 0 errors and 6 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 rails, grille bars and mirror heads are deliberately nested on their panels. One flags 'detached' parts: each sits alone in its own group, but they rest on each other. The last flags the 3 m height against the direction's 1 m reference. 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. three-check accepts those ids, and all 14 survive the GLB reload.