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FlexiKnobs are a set of slick mouse-like controllers for quick and easy multipoint interaction with audio software. A user simply points a FlexiKnob to an on-screen control element to adjust the corresponding software parameter. Assignments between an on-screen control and a FlexiKnob can be easily locked and released on-the-fly, without interrupting the user’s workflow.

The current version of the FlexiKnobs offers four different control modes: direct VST-control for virtual software instruments, MIDI, OSC and standard mouse-events. Users are free to choose which mode to use.

In MIDI-mode, the system provides a quick way to assign an arbitrary amount of MIDI-enabled on-screen controls to a handful of FlexiKnobs, using the simple mouse-like interaction paradigm. Whenever a user brings one FlexiKnob cursor over an assigned on-screen control element, the corresponding software parameter becomes adjustable. On turning the knob, the FlexiKnob system triggers the corresponding MIDI events. The mapping between the on-screen control positions and their corresponding MIDI events can be defined on-the-fly without interrupting the workflow, alternatively pre-generated mappings can be loaded.

All MIDI events are sent as standard MIDI-control changes. To overcome the low precision of MIDI and other issues inherent to the MIDI-protocol, the FlexiKnob system can also send OSC-messages.

The FlexiKnobs system software also comes with a custom VST-host that provides even greater control precision. Instead of controlling a VST plugin through MIDI or standard mouse events, the host controls the plugin directly ‘from behind’ via the VST-interface, while providing the user with the familiar mouse/knob interaction paradigm.

No matter which mode is active, once a parameter assignment is made, the related application window can be moved around freely, resized or hidden without breaking the parameter assignment. The circular cursor that displays the current mapping of each FlexiKnob always stays above the assigned control. The user might also rearrange the FlexiKnobs to fit the layout of the on-screen controls without breaking the control mapping.

Besides this, plain-old mouse interaction using standard scrollwheel-and click events remains possible, even across different applications. In mouse-mode, FlexiKnobs enable systemwide multipoint interaction,
allowing the user to control any application that reacts to mouse input with several cursors at once. Its use is therefore not just limited to controlling audio software but could be used in many other settings as well…


Parameters in audio or video editing applications can mostly be controlled by a variety of hardware devices such as MIDI controllers. These, however, usually feature only a limited number of physical knobs arranged in a fixed layout. The hundreds of parameters offered by typical editing software across dozens of windows with distinct arrangements of on-screen controls are hard to map to such a fixed physical interface. To improve this, we have built a set of wireless, mouse-like devices enhanced with rotary controllers aiming at integrating the flexibility and transparency of mouse interaction with the benefits of physical controllers. Our software enables the simultaneous use of several of these knobs with a large variety of standard software.

The initial version of the FlexiKnobs