{
  "nodes": [
    {
      "node_id": 0,
      "parent_id": -1,
      "name": "object",
      "joint": "root"
    },
    {
      "node_id": 1,
      "parent_id": 2,
      "name": "door",
      "joint": "hinge"
    },
    {
      "node_id": 2,
      "parent_id": 0,
      "name": "surface",
      "joint": "static"
    }
  ],
  "edges": [
    {
      "source": 2,
      "target": 1
    },
    {
      "source": 0,
      "target": 2
    }
  ]
}