{
  "catalog_id": 19,
  "title": "Recently alighted pupils dart around a stopped school bus",
  "source_template": "cargo",
  "summary": "Counterfactual proposal: four recently alighted pupils walk along the curb side of a stopped school bus. The leader abruptly runs around its front, and the others follow in a staggered burst across ego's path. A supervisor follows and regroups them on the north sidewalk. The bus remains partly in ego's corridor with warning lamps active, so ego does not resume.",
  "focus_xy": [
    41,
    1
  ],
  "initial_review_time_s": 1,
  "ego_stop_x_m": 12,
  "ego_release_s": -1,
  "events": [
    {
      "time_s": -7,
      "label": "Stopped school bus and four already-alighted pupils are present beside its curb side"
    },
    {
      "time_s": -4,
      "label": "Leading pupil approaches the bus nose at walking speed"
    },
    {
      "time_s": -3,
      "label": "Leader rounds the nose and suddenly begins running; ego is already stopped"
    },
    {
      "time_s": -1,
      "label": "Leader enters the ego corridor as the second pupil rounds the nose"
    },
    {
      "time_s": 1,
      "label": "Second pupil crosses the corridor while the third begins the same sudden dash"
    },
    {
      "time_s": 5,
      "label": "Last pupil crosses the ego corridor; supervisor continues following"
    },
    {
      "time_s": 12.9,
      "label": "All four pupils reach distinct waiting positions on the north sidewalk"
    },
    {
      "time_s": 16,
      "label": "Supervisor maintains a stop signal; the school bus remains a corridor obstruction"
    },
    {
      "time_s": 40,
      "label": "Group remains supervised and bus remains stopped; no ego release"
    }
  ],
  "actors": [
    {
      "id": "c019_bus",
      "label": "Stopped school bus with active warning lamps",
      "kind": "bus",
      "role": "Stationary school bus providing the front-corner occlusion and persistent lane obstruction",
      "color": "yellow",
      "length_m": 8.2,
      "width_m": 2.5,
      "height_m": 3.1,
      "keys": [
        {
          "t": -7,
          "x": 35,
          "y": -2.25,
          "z": 0,
          "heading_deg": 4.65,
          "pose": "stand"
        },
        {
          "t": -3,
          "x": 35,
          "y": -2.25,
          "z": 0,
          "heading_deg": 4.65,
          "pose": "stand"
        },
        {
          "t": 1,
          "x": 35,
          "y": -2.25,
          "z": 0,
          "heading_deg": 4.65,
          "pose": "stand"
        },
        {
          "t": 16,
          "x": 35,
          "y": -2.25,
          "z": 0,
          "heading_deg": 4.65,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 35,
          "y": -2.25,
          "z": 0,
          "heading_deg": 4.65,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "The bus remains stationary, approximately parallel to the mapped south curb. Its curb-side door and warning lamps are integral vehicle components. The door remains open and warning lamps remain active. Children pass beyond the frontmost vehicle footprint rather than through its body."
    },
    {
      "id": "c019_p1",
      "label": "Leading pupil who darts out first",
      "kind": "child",
      "role": "First of exactly four recently alighted pupils",
      "color": "blue",
      "length_m": 0.38,
      "width_m": 0.38,
      "height_m": 1.25,
      "keys": [
        {
          "t": -7,
          "x": 37.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": -4,
          "x": 40.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": -3,
          "x": 41,
          "y": -4.5,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": -1,
          "x": 41,
          "y": 0.9,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 3,
          "x": 41,
          "y": 11.7,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 4.5,
          "x": 41,
          "y": 15,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 5.5,
          "x": 41.8,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 11.1,
          "x": 47.4,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 13,
          "x": 47.4,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 47.4,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Walks beside the bus, makes a rounded turn beyond its nose, then unexpectedly accelerates across the road. On the north sidewalk the pupil slows, turns east, and makes room for the followers before waiting."
    },
    {
      "id": "c019_p2",
      "label": "Second pupil following the leader",
      "kind": "child",
      "role": "Second of exactly four recently alighted pupils",
      "color": "orange",
      "length_m": 0.4,
      "width_m": 0.4,
      "height_m": 1.32,
      "keys": [
        {
          "t": -7,
          "x": 35.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": -2,
          "x": 40.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": -1,
          "x": 41,
          "y": -4.5,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 1,
          "x": 41,
          "y": 0.9,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 5,
          "x": 41,
          "y": 11.7,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 6.5,
          "x": 41,
          "y": 15,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 7.5,
          "x": 41.8,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 11.7,
          "x": 46,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 13,
          "x": 46,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 46,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Follows the leader's route with a two-second delay, preserving spacing around the bus nose and across the road. Stops at a distinct north-side waiting position."
    },
    {
      "id": "c019_p3",
      "label": "Third pupil joining the dash",
      "kind": "child",
      "role": "Third of exactly four recently alighted pupils",
      "color": "lime",
      "length_m": 0.41,
      "width_m": 0.41,
      "height_m": 1.4,
      "keys": [
        {
          "t": -7,
          "x": 33.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 0,
          "x": 40.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 1,
          "x": 41,
          "y": -4.5,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 3,
          "x": 41,
          "y": 0.9,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 7,
          "x": 41,
          "y": 11.7,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 8.5,
          "x": 41,
          "y": 15,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 9.5,
          "x": 41.8,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 12.3,
          "x": 44.6,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 14,
          "x": 44.6,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 44.6,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Maintains the initial walking queue, then follows the sudden front-of-bus dash two seconds behind the second pupil. Does not cut through the bus or overtake another child."
    },
    {
      "id": "c019_p4",
      "label": "Last pupil emerging from the bus front",
      "kind": "child",
      "role": "Fourth and last of exactly four recently alighted pupils",
      "color": "teal",
      "length_m": 0.42,
      "width_m": 0.42,
      "height_m": 1.46,
      "keys": [
        {
          "t": -7,
          "x": 31.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 2,
          "x": 40.2,
          "y": -5.3,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 3,
          "x": 41,
          "y": -4.5,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 5,
          "x": 41,
          "y": 0.9,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 9,
          "x": 41,
          "y": 11.7,
          "z": 0,
          "heading_deg": 90,
          "pose": "run"
        },
        {
          "t": 10.5,
          "x": 41,
          "y": 15,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 11.5,
          "x": 41.8,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "walk"
        },
        {
          "t": 12.9,
          "x": 43.2,
          "y": 15.8,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 14.5,
          "x": 43.2,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 43.2,
          "y": 15.8,
          "z": 0,
          "heading_deg": -90,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "The final child repeats the front-corner emergence after the others rather than appearing from nowhere. Remains identifiable and stops separately at the rear of the regrouped line."
    },
    {
      "id": "c019_staff",
      "label": "School group supervisor",
      "kind": "human",
      "role": "Adult responding to the sudden dash and regrouping the four pupils",
      "color": "navy",
      "length_m": 0.48,
      "width_m": 0.52,
      "height_m": 1.74,
      "keys": [
        {
          "t": -7,
          "x": 44.6,
          "y": -5.7,
          "z": 0,
          "heading_deg": 180,
          "pose": "stand"
        },
        {
          "t": -3,
          "x": 44.6,
          "y": -5.7,
          "z": 0,
          "heading_deg": 90,
          "pose": "stop_signal"
        },
        {
          "t": 0,
          "x": 44.6,
          "y": -2.1,
          "z": 0,
          "heading_deg": 90,
          "pose": "stop_signal"
        },
        {
          "t": 5,
          "x": 44.6,
          "y": 4.4,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 10,
          "x": 44.6,
          "y": 10.9,
          "z": 0,
          "heading_deg": 90,
          "pose": "walk"
        },
        {
          "t": 14,
          "x": 44.6,
          "y": 14.6,
          "z": 0,
          "heading_deg": 90,
          "pose": "point"
        },
        {
          "t": 16,
          "x": 44.6,
          "y": 14.6,
          "z": 0,
          "heading_deg": 180,
          "pose": "stop_signal"
        },
        {
          "t": 40,
          "x": 44.6,
          "y": 14.6,
          "z": 0,
          "heading_deg": 180,
          "pose": "stop_signal"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Responds to the leader's dash with a stop signal, walks across on a separate track at x=44.6, and directs the pupils to their waiting positions. The final signal continues to hold traffic; no release gesture is given."
    }
  ],
  "acceptance_checks": [
    "Verify exactly one school bus, four individually identified pupils, and one supervisor persist through all 941 samples.",
    "Verify all four pupils are visibly present outside the bus at -7 s; none spawns at the door, traverses the bus body, disappears, or duplicates.",
    "Verify the bus footprint remains wholly on the cargo road polygon and every pupil rounds its front with positive body clearance.",
    "Verify the walking queue maintains at least 0.6 m body separation, the two-second stagger persists through the dash, and the final waiting positions do not overlap.",
    "Verify walking phases remain within 0.6–1.7 m/s and running phases within 2–4 m/s apart from smooth gait transitions; rounded turns must not create instantaneous heading flips.",
    "Verify the bus creates real front-corner occlusion from ego's viewpoint while allowing continuous emergence; human review must confirm this against the original camera.",
    "Verify all final pedestrian footprints fit the north sidewalk, but do not infer ego clearance: the bus still intersects the buffered corridor and remains stopped with warning lamps active.",
    "Verify ego stays at x=12 through 40 s with ego_release_s=-1, and require human approval before image generation."
  ],
  "assumptions": [
    "Image #3 supplies the broad street, marked roadway strips, fences, trees, and parked-car context. The school bus, pupils, supervisor, and all motion are counterfactual additions rather than observed events.",
    "The unspecified group is instantiated as exactly four pupils and one supervisor. All four completed disembarkation before -7 s and begin already outside the bus, lining up beside its curb side; this avoids invented interior geometry, stair-height jumps, or concealed spawning.",
    "Playback covers -7 through 40 s inclusive at 20 Hz: 941 samples, finite and non-looping. Use bounded C1 trajectories, approximately rounded 0.8 m corner turns, smooth gait transitions, and exact stationary final holds.",
    "The bus follows the supplied cargo map's sloping south curb at heading 4.65 degrees. The pupils approach along y=-5.3, cross at x=41 beyond the bus nose, and regroup at y=15.8 inside the mapped north sidewalk. All standing and wheeled support roots use z=0.",
    "Ego is separate from the six listed actors: 4.5 m long, 1.9 m wide, y=0, starting at x=4 at -7 s with speed 4 m/s and stopping smoothly at x=12 by -3 s. The buffered corridor is y=-1.5 to 1.5.",
    "The school bus intentionally remains stopped for the entire rehearsal. Its front-side footprint intrudes into the ego corridor, so pedestrian clearance alone cannot authorize resumption. No bus departure or overtaking maneuver is invented.",
    "The bus door and lamps are integral rigged components; no additional pupils, bags, or freestanding stop-sign props are assumed. Background parked-vehicle footprints and exact occlusion require human review.",
    "Approval is pending. Later Image 2.5 must edit original Image #3, preserving source architecture and using this rehearsal only for actor position and posture."
  ]
}