Point Calibration

Node ID: pointCalibration · Role: Sink · Realtime config: no

Description

Marks known real-world points with a tracked stylus body and solves the rigid transform that aligns the optical tracking frame with a set of virtual reference points (e.g. collapse a virtual cube onto its real counterpart). With a Target Body wired, points are instead measured in that body’s frame, solving the transform from the body’s tracked frame to the reference (e.g. CAD) frame - apply it to the DTrack body to re-frame its marker geometry. Includes a pivot calibration that recovers the stylus tip offset by rotating the stylus around a fixed tip.

Inputs / Outputs

Inputs: Optical - Stylus, TargetBody (Optical) - Target Body
Outputs: (none)

Properties

The following fields are exposed in the node’s Properties panel in the UI. Types map to UI widgets (e.g. string → text input, number → numeric, boolean → toggle, select → dropdown, json → JSON editor).

Key	Label	Type	Default	Description / Notes
`tipOffset`	Stylus Tip Offset	`vector3`	`{"x":0.0,"y":0.0,"z":0.0}`	Offset from the tracked stylus body origin to its physical tip, in the body frame (m). Solve it with the pivot calibration in the Point Alignment view.
`captureWindowMs`	Capture Window (ms)	`number`	`750`	hidden in UI

Example node definition

A full node definition in config.json looks like the block below. Paste it under the sinks key of your config, keyed by the node’s instance name (any identifier; it doesn’t have to match the node ID).

{
  "sinks": {
    "pointCalibration": {
      "inputEndpoints": [
        "inproc://optical_data",
        "inproc://targetBody_data"
      ],
      "inputDataFilter": [
        "Optical",
        "Optical"
      ],
      "settings": {
        "captureWindowMs": 750,
        "tipOffset": {
          "x": 0.0,
          "y": 0.0,
          "z": 0.0
        }
      }
    }
  }
}

Field reference

Field	Purpose
`inputEndpoints`	List of upstream endpoints this node connects to (`outEndpoint` / `dataEndpoint` values from upstream nodes).
`inputDataFilter`	Optional whitelist of data types. Messages whose type isn’t in the list are dropped at the subscriber.
`settings`	All user-configurable fields — see the Properties table above.

Connections can also be declared at the top-level connections array when settings.explicitConnections is true, as an alternative to filling inputEndpoints on each node.

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