{
  "catalog_id": 28,
  "title": "Half-crouched road-marking worker overlooking rear traffic",
  "source_template": "cargo",
  "summary": "Counterfactual rehearsal: a worker refreshes a short road stripe, repeatedly half-crouching and concentrating on the applicator rather than approaching traffic behind. The worker and protected work area remain in the ego corridor through the final state.",
  "focus_xy": [
    35.2,
    0.25
  ],
  "initial_review_time_s": 2,
  "ego_stop_x_m": 13,
  "ego_release_s": -1,
  "events": [
    {
      "time_s": -7,
      "label": "Worker stands beside the grounded applicator inside the established work area"
    },
    {
      "time_s": -4,
      "label": "Worker half-crouches and begins refreshing the existing guide stripe"
    },
    {
      "time_s": 0,
      "label": "Ego finishes stopping upstream; worker continues facing away from rear traffic"
    },
    {
      "time_s": 2,
      "label": "Peak focused reach: the worker advances the roller without looking behind"
    },
    {
      "time_s": 12,
      "label": "Worker resumes half-crouched marking at the second station"
    },
    {
      "time_s": 28,
      "label": "Second walking transfer ends at the third work station"
    },
    {
      "time_s": 30,
      "label": "Worker lowers into another half-crouch and begins the final short pass"
    },
    {
      "time_s": 40,
      "label": "Worker remains crouched over unfinished work; cones and equipment still obstruct the corridor"
    }
  ],
  "actors": [
    {
      "id": "c028_worker",
      "label": "Road-marking worker focused away from rear traffic",
      "kind": "human",
      "role": "Adult operator who refreshes the stripe in three short working stations and does not acknowledge ego",
      "color": "orange",
      "length_m": 0.56,
      "width_m": 0.52,
      "height_m": 1.75,
      "keys": [
        {
          "t": -7,
          "x": 32,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": -4,
          "x": 32,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "crouch"
        },
        {
          "t": 2,
          "x": 32,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "crouch"
        },
        {
          "t": 6,
          "x": 32,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "push"
        },
        {
          "t": 10,
          "x": 35.2,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "push"
        },
        {
          "t": 12,
          "x": 35.2,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "crouch"
        },
        {
          "t": 24,
          "x": 35.2,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "push"
        },
        {
          "t": 28,
          "x": 38.4,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "push"
        },
        {
          "t": 30,
          "x": 38.4,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "crouch"
        },
        {
          "t": 40,
          "x": 38.4,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "crouch"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Crouch denotes a half-squat, not kneeling. Hands contact the applicator's rear-facing lower grip about 0.35-0.55 m ahead of the body and 0.62 m above ground. During walking transfers, hands use its upper grip at approximately 0.95 m. Head and torso remain directed toward the marking work."
    },
    {
      "id": "c028_roller",
      "label": "Hand-pushed narrow road-paint applicator",
      "kind": "equipment",
      "role": "Ground-supported roller with a compact paint reservoir and a sloping handle with lower and upper grips",
      "color": "yellow",
      "length_m": 0.6,
      "width_m": 0.28,
      "height_m": 0.98,
      "keys": [
        {
          "t": -7,
          "x": 32.65,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": -4,
          "x": 32.65,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 2,
          "x": 32.85,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 6,
          "x": 32.65,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 10,
          "x": 35.85,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 12,
          "x": 36.05,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 24,
          "x": 35.85,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 28,
          "x": 39.05,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 30,
          "x": 39.25,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 39.05,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "The independently keyed applicator stays on its wheels while the operator varies arm extension. Its rear grip is 0.30 m behind its root; the paint roller contacts the stripe ahead of the root. The two walking transfers remain synchronized with the operator without towing gaps or body penetration."
    },
    {
      "id": "c028_pail",
      "label": "Road-paint supply pail",
      "kind": "equipment",
      "role": "Stationary paint supply already present before rehearsal",
      "color": "white",
      "length_m": 0.34,
      "width_m": 0.34,
      "height_m": 0.38,
      "keys": [
        {
          "t": -7,
          "x": 31.3,
          "y": -1.4,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 31.3,
          "y": -1.4,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Remains beside the working route without being picked up, duplicated, or moved into the operator's footsteps."
    },
    {
      "id": "c028_stripe",
      "label": "Short white guide stripe being refreshed",
      "kind": "equipment",
      "role": "Persistent surface-applied marking, represented as a thin non-solid decal",
      "color": "white",
      "length_m": 7.8,
      "width_m": 0.12,
      "height_m": 0.003,
      "keys": [
        {
          "t": -7,
          "x": 35.9,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 35.9,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Conforms to the mapped road surface. This is an existing rehearsal guide stripe receiving a fresh coat, so its full extent is present from the start rather than appearing instantaneously."
    },
    {
      "id": "c028_cone_w",
      "label": "Upstream work-zone cone",
      "kind": "cone",
      "role": "Persistent upstream warning and corridor obstruction",
      "color": "orange",
      "length_m": 0.45,
      "width_m": 0.45,
      "height_m": 0.7,
      "keys": [
        {
          "t": -7,
          "x": 28,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 28,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Stays upstream of the worker throughout; it is not removed to manufacture ego clearance."
    },
    {
      "id": "c028_cone_e",
      "label": "Downstream work-zone cone",
      "kind": "cone",
      "role": "Persistent downstream boundary of the short marking operation",
      "color": "orange",
      "length_m": 0.45,
      "width_m": 0.45,
      "height_m": 0.7,
      "keys": [
        {
          "t": -7,
          "x": 41.8,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 41.8,
          "y": 0.25,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Remains beyond the final roller position with clear space for the operator's last work station."
    }
  ],
  "acceptance_checks": [
    "Sample the finite interval [-7,40] at 20 Hz, producing 941 inclusive states; retain all six critical IDs throughout.",
    "Check every support point and solid footprint against the supplied cargo road polygon, including interpolated states.",
    "Verify the two 3.2 m walking transfers occur over four seconds each, with smooth acceleration and no walking speed above 1.7 m/s.",
    "Verify half-crouched posture, hands ahead on the applicator grips, ground contact at the roller, and no torso-tool penetration.",
    "Keep the worker facing the work rather than acknowledging rear traffic; the scene must visibly depict road marking rather than a generic pedestrian crossing.",
    "Keep ego stopped at x=13 near y=0 from time 0 onward. Worker, cones, and equipment prevent release through time 40.",
    "Obtain human approval of the full timeline and the initial review state before Image 2.5 edits the original cargo photo; preserve the original architecture."
  ],
  "assumptions": [
    "Observed evidence is limited to Image 3 and the supplied cargo map: a paved urban street, sidewalks, and road markings. The worker, equipment, cones, and guide stripe are counterfactual additions.",
    "All coordinates are newly authored on this map. The critical cast contains one adult and five individually identified props; ego is separately controlled.",
    "Playback is non-looping from -7 to 40 seconds at 20 Hz. Use continuous, bounded motion between keys and hold explicit rest states.",
    "All ground-supported roots use z=0 relative to the supplied mapped ground surface. The stripe is a surface decal, not a raised obstacle.",
    "The short stripe is a local repainting task, not an asserted change to the source map's lane topology.",
    "Background-object occupancy and fine curb geometry are not fully specified by the polygons and must be checked against the original photo during human review.",
    "This JSON is a proposed rehearsal, not a claim that simulation checks or image generation have been performed."
  ]
}