{
  "source": {
    "run": "RoboDojo make_toast, seed 0, layout 011",
    "trace_rate_hz": 25,
    "physics_callback_rate_hz": 250,
    "raw_trace_redistributed": false,
    "raw_trace_bytes": 2623465,
    "raw_trace_sha256": "f074ee2c33896f6f293fef082a5408c648236ff57a24fdef51e0c82ee385adcd"
  },
  "method": {
    "orientation": "bread pose relative to the wrist at step 180",
    "edge_margin": "mean distance from the two recorded finger-contact proxies to the top edge of an oriented bounding-box proxy",
    "acceleration": "finite difference of the 25 Hz wrist pose",
    "limits": [
      "The edge margin uses an OBB proxy, not the native PhysX collision mesh.",
      "The trace does not contain full tangential impulse or the resolved runtime material pair.",
      "The 25 Hz finite differences cannot uniquely separate friction, compliance, collision-mesh and acceleration contributions."
    ]
  },
  "first_failing_layer": "shallow grasp geometry loses edge margin during in-plane rotation",
  "causal_chain": [
    "The grasp starts only about 14 mm below the top edge.",
    "Upward wrist acceleration raises effective load while the slice rotates in the gripper plane.",
    "The two contact proxies roll toward the top edge and lose geometric support.",
    "Bilateral normal impulse collapses while the close command remains active.",
    "The empty fingers close farther and the slice enters free fall."
  ],
  "timeline": [
    {
      "step": 186,
      "relative_in_plane_rotation_deg": 6.93,
      "mean_top_edge_margin_mm": 14.41,
      "bilateral_normal_impulse_ns": 0.25257323127599374
    },
    {
      "step": 187,
      "relative_in_plane_rotation_deg": 10.08,
      "mean_top_edge_margin_mm": 9.66,
      "bilateral_normal_impulse_ns": 0.2497
    },
    {
      "step": 188,
      "relative_in_plane_rotation_deg": 12.45,
      "mean_top_edge_margin_mm": 2.87,
      "bilateral_normal_impulse_ns": 0.0018726327716308989
    }
  ],
  "amplifier": {
    "peak_upward_wrist_acceleration_m_s2": 4.58,
    "peak_steps": [181, 182, 183],
    "interpretation": "The lift transient is a plausible amplifier of a shallow, torsionally weak grasp, not a uniquely identified parameter-level root cause."
  },
  "post_release": {
    "first_table_impact_step": 192,
    "first_table_impact_impulse_ns": 0.11085090041160583,
    "external_impulse_before_release_ns": 0.0
  },
  "proven": [
    "The close command remains active.",
    "In-plane rotation and loss of top-edge margin precede the normal-impulse collapse.",
    "No neighbor or shelf impact is recorded before release.",
    "The table impact occurs after contact loss."
  ],
  "not_proven": [
    "A PhysX solver defect",
    "An exact friction coefficient error",
    "A unique contribution from missing fingertip or bread compliance",
    "Hardware bread behavior"
  ]
}