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Announcing Geco for Leap

This is a first look at the application that I’ve been working on for the Leap Motion Controller. It provides multi-dimensional MIDI expression through hand gestures.

Geco has been designed for live performance and it operates at extremely low latency, while requiring very little resources on your computer. It can thus perfectly run alongside any MIDI capable software.

In this demo I show some of the configuration capabilities while using Native Instrument’s Razor synth in Reaktor.

Notable Features:

  • 40 different control streams with both hands
  • any control stream can be mapped to MIDI CC and Pitchbend messages on 16 different channels
  • instantly switch between related control streams by opening or closing your hands
  • carefully designed GUI for an immediate overview of the active MIDI mappings
  • real-time low-latency visual feedback of your hand movements and MIDI data
  • integrated virtual MIDI port on MacOSX
  • connects to any known MIDI output port on your computer
  • fully customisable user interface (colours, graphical elements)
  • flexible document management that can be loaded while performing gestures
  • high performance and near-zero latency engine with virtually no CPU impact when the real-time visualisations are hidden
  • MIDI decimation setting to allow integration with legacy hardware that has limited MIDI bandwidth


Posted in Controllers, Setup.

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3 Responses

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  1. Torsten Anders says

    Impressive! Even more so considering that this is only a $79.99 device, and that you apparently wrote this Leap agent rather quickly. Great!

    How sensitive is the Leap Motion Controller? If you use the full MIDI CC range of 128, how difficult is it to make only very small changes?

    How do you get 40 different control streams. From what you explained I understand there are 3 different directions (X, Y, Z) x open vs. close hands x left vs right hand = 12 controllers (which is already a lot). Where do the others come from?



    • Geert says

      The Leap is extremely sensitive, it feels like an instrument and the latency is only a couple of milliseconds (still need to find a good way to measure it, maybe a high frame rate video camera).

      You can use pitchbend messages over 16 channels, giving you 14 bit resolution. I refrained from implementing 14 bit MIDI CC since almost nothing uses it.

      X position, X distance from first seen, Y pos, Y dist, Z pos, Z dist, pitch, roll, yaw, hand presence … for both hands and for both openness states. That’s 40 🙂

  2. Andrejs says

    I wonder if it’s Leap Motion driver/device itself or Geco that uses considerable amount of CPU even when Low resource mode is set to ON in the Leap Motion Control Panel, which sometimes may get to the point of clicks and distortion in the output audio as CPU cannot handle so much at once. Often I find it not being able to use Leap Motion with Geco on stage due to these issues. Sad..

    I am on a Mac Book Pro 8,2 (i7) running Mac OS X 10.8.5.

    Any advice on how light on CPU is Geco application itself would be recommended. Future updates with possible fixes are even more welcome.


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