{
  "version": "0.1",
  "nodes": {
    "1": { "id": 1, "name": "Bottom cube", "op": { "type": "Cube", "size": { "x": 40, "y": 40, "z": 10 } } },
    "2": { "id": 2, "name": "Bottom positioned", "op": { "type": "Translate", "child": 1, "offset": { "x": -20, "y": -20, "z": 0 } } },
    "3": { "id": 3, "name": "Middle cube", "op": { "type": "Cube", "size": { "x": 28, "y": 28, "z": 10 } } },
    "4": { "id": 4, "name": "Middle positioned", "op": { "type": "Translate", "child": 3, "offset": { "x": -14, "y": -14, "z": 10 } } },
    "5": { "id": 5, "name": "Top cube", "op": { "type": "Cube", "size": { "x": 16, "y": 16, "z": 10 } } },
    "6": { "id": 6, "name": "Top positioned", "op": { "type": "Translate", "child": 5, "offset": { "x": -8, "y": -8, "z": 20 } } },
    "7": { "id": 7, "name": "Bottom+Middle", "op": { "type": "Union", "left": 2, "right": 4 } },
    "8": { "id": 8, "name": "Stepped pyramid", "op": { "type": "Union", "left": 7, "right": 6 } }
  },
  "materials": {},
  "part_materials": {},
  "roots": [
    { "root": 8, "material": "default" }
  ]
}