Layout
These are arrays of strings where each line represents a block layout like you where looking down on a slice of your machine.
The top of the array is north, bottom south, right is east, left is west
Each array is a different Y level in your structure, the top layer in the file is the very top layer of your structure
A capital C is specifically reserved for the controller, this is automatically defined by setting the controllerId at the top of the file
For a structure file to be valid it needs to have a capital C in the layout somewhere
The code below is of a 3x3x3 structure, where...
- 1 = cobblestone (Very top layer)
 - 2 = stone (Central layer)
 - 3 = oak_log (Very bottom layer)
 - C = the controller
 
"layout": [
  [
    "111",
    "111",
    "111"
  ],
  [
    "2C2",
    "222",
    "222"
  ],
  [
    "333",
    "333",
    "333"
  ]
]