Pinch Detection Example (Python)

rgmp_pinch_detector.py reads the driver’s RGMP stream and prints one line each time a thumb pinch starts or ends — thumb to index, middle, ring or pinky, on either hand. What you do with a pinch is up to you; the example prints and stops there.

flowchart LR
    Driver["SDK Driver<br/>rokoko-sdk"]
    Detector["rgmp_pinch_detector.py"]
    Out["One line per event<br/>on stdout"]

    Driver -->|"TCP :12276 (RGMP)"| Detector
    Detector --> Out

Note

Python 3.10+ with NumPy and SciPy — unlike the other Python examples, this one is not standard library only. uv run fetches both into a throwaway environment; without uv, pip install numpy scipy.

Running it

Start the driver with --auto-stream-usb so it streams the gloves (see Streaming data):

rokoko-sdk --auto-stream-usb

Then, from $ROKOKO_SDK_HOME/examples/python:

uv run rgmp_pinch_detector.py      # or: python3 rgmp_pinch_detector.py

It reads both gloves, left and right, at the same time, and each event names the hand that made it. Other devices on the same driver are named on stderr and ignored.

What it prints

Pinch  left  thumb_index   fired     #2     ...I|....
Pinch  right thumb_ring    fired     #1     ...I|..R.
Pinch  left  thumb_index   released  #2     ....|..R.

• fired when the fingers meet, released when the pinch ends. Every fired is closed by exactly one released, so you can pair them directly.
• The lanes on the right show all eight pinches at once, left hand then right, a letter for each one held.
• released means the hand stopped looking like that pinch, not the moment the fingertips parted — expect it a few hundred milliseconds after the fingers separate.

Flags

Flag	Default	Purpose
--host	127.0.0.1	Driver host.
--port	12276	Driver RGMP port.
--threshold-scale	1.0	Scales all four collision thresholds; above 1 is stricter, below 1 looser. Reach for it first when pinches under- or over-fire.
--orientations	fingers_up,edge_down	Hand attitudes a pinch is accepted in, comma separated, or any.
--verbose	—	Also print each event’s sensor clock. The clock is per glove and not comparable between gloves.

How the source is laid out

The detector is a small package, pinch_detection/, driven by rgmp_pinch_detector.py, so it isn’t reproduced here — read it in $ROKOKO_SDK_HOME/examples/python. It reuses rgmp_core for the RGMP client and solver_core for which sensor a stream belongs to, the same packages as the Hand Solver example.

Where to go next

• Hand Solver (Python) — the same glove stream, solved into 26-joint hands.
• RGMP specification — the wire format the detector reads.