{
  "externalDevices": {
    "/myExternalDevice": {
      "deviceName": "Tracker0",
      "server": "localhost:3664",
      "descriptor": /* can also provide a file path here, or this is the minimal */ {
        "interfaces": {
          "tracker": {},
          "button": {},
          "analog": {}
        }
      }
    }
  },
  "aliases": {
    "/me/head": {
      "rotate": {
        "axis": "-x",
        "degrees": 180
      },
      "child": {
        "changeBasis": {
          "x": "x",
          "y": "-z",
          "z": "-y"
        },
        "child": "/myExternalDevice/tracker/0"
      }
    },
    "/me/hands/right": {
      "rotate": {
        "axis": "-x",
        "degrees": 180
      },
      "child": {
        "changeBasis": {
          "x": "x",
          "y": "-z",
          "z": "-y"
        },
        "child": "/myExternalDevice/tracker/1"
      }
    },
    "/controller/trigger": "/myExternalDevice/analog/0",
    "/controller/a": "/myExternalDevice/button/0"
  }
}

{
  "externalDevices": {
    "/myExternalDevice": {
      "deviceName": "Tracker0",
      "server": "localhost:3884",
      "descriptor": /* can also provide a file path here, or this is the minimal */ {
        "interfaces": {
          "tracker": {},
          "button": {},
          "analog": {}
        }
      }
    }
  },
  "aliases": {
    "/me/head": {
      "rotate": {
        "axis": "-x",
        "degrees": 180
      },
      "child": {
        "changeBasis": {
          "x": "x",
          "y": "-z",
          "z": "-y"
        },
        "child": "/myExternalDevice/tracker/0"
      }
    },
    "/me/hands/right": {
      "rotate": {
        "axis": "-x",
        "degrees": 180
      },
      "child": {
        "changeBasis": {
          "x": "x",
          "y": "-z",
          "z": "-y"
        },
        "child": "/myExternalDevice/tracker/1"
      }
    },
    "/controller/trigger": "/myExternalDevice/analog/0",
    "/controller/a": "/myExternalDevice/button/0"
  }
}

Change port in example external VRPN config file.
Change port in example external VRPN config file.
