{
  "version": "0.1",
  "nodes": {
    "1": { "id": 1, "name": "plate_cube", "op": {"type": "Cube", "size": {"x": 50, "y": 30, "z": 10}} },
    "2": { "id": 2, "name": "plate_centered", "op": {"type": "Translate", "child": 1, "offset": {"x": -25, "y": -15, "z": 0}} },

    "10": { "id": 10, "name": "hole1_cyl", "op": {"type": "Cylinder", "radius": 1.5, "height": 10, "segments": 32} },
    "11": { "id": 11, "name": "hole1", "op": {"type": "Translate", "child": 10, "offset": {"x": -20, "y": -10, "z": 0}} },

    "12": { "id": 12, "name": "hole2_cyl", "op": {"type": "Cylinder", "radius": 1.5, "height": 10, "segments": 32} },
    "13": { "id": 13, "name": "hole2", "op": {"type": "Translate", "child": 12, "offset": {"x": 20, "y": -10, "z": 0}} },

    "14": { "id": 14, "name": "hole3_cyl", "op": {"type": "Cylinder", "radius": 1.5, "height": 10, "segments": 32} },
    "15": { "id": 15, "name": "hole3", "op": {"type": "Translate", "child": 14, "offset": {"x": -20, "y": 10, "z": 0}} },

    "16": { "id": 16, "name": "hole4_cyl", "op": {"type": "Cylinder", "radius": 1.5, "height": 10, "segments": 32} },
    "17": { "id": 17, "name": "hole4", "op": {"type": "Translate", "child": 16, "offset": {"x": 20, "y": 10, "z": 0}} },

    "20": { "id": 20, "name": "diff1", "op": {"type": "Difference", "left": 2, "right": 11} },
    "21": { "id": 21, "name": "diff2", "op": {"type": "Difference", "left": 20, "right": 13} },
    "22": { "id": 22, "name": "diff3", "op": {"type": "Difference", "left": 21, "right": 15} },
    "23": { "id": 23, "name": "diff4", "op": {"type": "Difference", "left": 22, "right": 17} }
  },
  "materials": {},
  "part_materials": {},
  "roots": [{ "root": 23, "material": "default" }]
}