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Tracking zones to MIDI

Pulse to Midi connected to Midi scale and Midi Envelope in the tracking patch

Turn zone-entry events into notes and inspect the tracking data that triggers them.

Try this on web

Download the example

Requirements

Install ONNX/Pose Detector support and the LivePose model pack. RetinaFace uses packages/pose-detector/detectors/det-face-retinaface-mobile.onnx in the user library. The graph also uses the default Presets/Javascript/tracking-zones/tracking-zones.qml preset, Jk Object filter, FoMo from Synthimi, Airwindows, and Faust. Select a camera for Camera:/ and a working audio output for audio:/out/main.

Run and inspect

Open tracking-zones’ custom interface and start playback. Simulation is enabled in the saved patch: use it to inspect zone events independently of camera detection, then turn it off to work with real face detections. Pose Detector’s Detection output is connected to Source 1. For a model configured for multiple independent detections, the Poses output is the corresponding collection to connect instead.

The Events output feeds two Object filters:

  • .[] | select(.type == "enter") | .zone writes zones:/enter.
  • .[] | select(.type == "exit") | .zone writes zones:/exit.

The OSC device listens on UDP 9997 and sends to 127.0.0.1:9996. Pulse to Midi reads zones:/enter, generates notes with default pitch 53 and pitch randomization 24, and sends them through a Lydian Midi scale into FoMo’s Port of Spain preset. The saved exit branch reports departures; it is not connected as a note-off command. Note duration is controlled by Pulse to Midi.

Expected result

Cross a configured zone boundary and compare the Events/Enter displays with MIDI display. The note envelope also modulates smoothDelay and IronOxideClassic2 before Lowpass2 reaches the parent audio mix. Begin quietly: the saved delay feedback is about 92.5%. The Lightness sampler receives the annotated camera texture but has no Positions connection or downstream Samples cable; it is not the note trigger in this graph.