{
  "source": "Nokov solved skeleton (vendor export, BVH/CSV Body0)",
  "rotation": "quaternions_xyzw are global segment orientations in the canonical frame",
  "note": "a few early sessions (20260903) carry an extra Spine4 joint; per-session joint_names are authoritative",
  "joints": [
    {
      "name": "Hips",
      "parent": null,
      "smplx": "pelvis"
    },
    {
      "name": "Spine",
      "parent": "Hips",
      "smplx": "spine1"
    },
    {
      "name": "Spine1",
      "parent": "Spine",
      "smplx": null
    },
    {
      "name": "Spine2",
      "parent": "Spine1",
      "smplx": "spine2"
    },
    {
      "name": "Spine3",
      "parent": "Spine2",
      "smplx": "spine3"
    },
    {
      "name": "LeftShoulder",
      "parent": "Spine3",
      "smplx": "left_collar"
    },
    {
      "name": "LeftArm",
      "parent": "LeftShoulder",
      "smplx": "left_shoulder"
    },
    {
      "name": "LeftForeArm",
      "parent": "LeftArm",
      "smplx": "left_elbow"
    },
    {
      "name": "LeftHand",
      "parent": "LeftForeArm",
      "smplx": "left_wrist"
    },
    {
      "name": "RightShoulder",
      "parent": "Spine3",
      "smplx": "right_collar"
    },
    {
      "name": "RightArm",
      "parent": "RightShoulder",
      "smplx": "right_shoulder"
    },
    {
      "name": "RightForeArm",
      "parent": "RightArm",
      "smplx": "right_elbow"
    },
    {
      "name": "RightHand",
      "parent": "RightForeArm",
      "smplx": "right_wrist"
    },
    {
      "name": "Neck",
      "parent": "Spine3",
      "smplx": "neck"
    },
    {
      "name": "Head",
      "parent": "Neck",
      "smplx": "head"
    },
    {
      "name": "LeftUpLeg",
      "parent": "Hips",
      "smplx": "left_hip"
    },
    {
      "name": "LeftLeg",
      "parent": "LeftUpLeg",
      "smplx": "left_knee"
    },
    {
      "name": "LeftFoot",
      "parent": "LeftLeg",
      "smplx": "left_ankle"
    },
    {
      "name": "LeftToeBase",
      "parent": "LeftFoot",
      "smplx": "left_foot"
    },
    {
      "name": "RightUpLeg",
      "parent": "Hips",
      "smplx": "right_hip"
    },
    {
      "name": "RightLeg",
      "parent": "RightUpLeg",
      "smplx": "right_knee"
    },
    {
      "name": "RightFoot",
      "parent": "RightLeg",
      "smplx": "right_ankle"
    },
    {
      "name": "RightToeBase",
      "parent": "RightFoot",
      "smplx": "right_foot"
    }
  ]
}