{
  "version": "0.1",
  "nodes": {
    "1": { "id": 1, "name": "Outer Cylinder", "op": { "type": "Cylinder", "radius": 25, "height": 5, "segments": 32 } },
    "2": { "id": 2, "name": "Inner Hole", "op": { "type": "Cylinder", "radius": 12.5, "height": 5, "segments": 32 } },
    "3": { "id": 3, "name": "Washer", "op": { "type": "Difference", "left": 1, "right": 2 } }
  },
  "materials": {},
  "part_materials": {},
  "roots": [{ "root": 3, "material": "default" }]
}