Mixing Real and Virtual Controls

A Microsoft project lets a touch screen control other hardware.

Large touch-screen tables have emerged as a useful way for several people to collaborate on projects like video editing or graphic design, but often these tasks require fine controls that can be difficult to simulate on a touch surface with limited resolution. When a person needs precision, it may be best to use a physical controller instead, says Dan Morris, a researcher at Microsoft.

Halo effect: This MIDI controller is surrounded by virtual controls. Four of the virtual buttons control discrete tasks, including playing or pausing a track. The physical knobs provide finer control of the same function than the four virtual sliders. Credit: Microsoft Research

Multimedia   Watch the touch screen and audio-editing hardware developed by Microsoft.

Morris and his colleagues have developed software for touch-screen surfaces that allows physical controls to be added to them. In addition, the software lets people define the functions that each knob, button, and slider on a controller will perform.

The researchers' system, called Ensemble, was presented on Monday at the Computer-Human Interaction (CHI 2009) Conference in Boston. It consists of a touch table, made by former Microsoft intern Bjoern Hartmann, which is six feet long and four feet wide, and several portable sound-editing controllers that connect to the computer that controls the surface. The table is similar to Microsoft's Surface, but larger. As with Surface, cameras underneath the tabletop are used to sense when a user touches the surface or when an object is placed on top of it.

The idea of incorporating traditional input devices like mouses or keyboards with a touch display is not new, but the Microsoft researchers show with Ensemble that it's possible to make hardware do more than a single specified task.

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Cameras within the Ensemble table detect a special tag on the bottom of each audio control box to recognize each box and determine its position on the surface. The software then produces an "aura" around each device, including touch-surface controls like "play," "pause," and "stop," and virtual sliders that correspond to physical knobs on the box.

A person can then edit a music track, for example, using both the physical device and the touch-surface controls. The virtual sliders can be used to zoom in on the audio waveform of a track, or to go to a different location on the waveform by panning. The physical knobs on the box perform the same function but offer much finer control. The system also allows a person to change the function of the knobs to, say, control the volume of a trumpet track instead.