Figure 1. Holo Wall interactive surface system [ 5]. The camera (with IR filter) captures the image on the back surface of a rear-projection sheet illuminated by IR lights behind the sheet. (a) Sensor configuration; (b) example multi-touch interaction; (c) physical instruments for interaction; (d) captured image for recognition; and (e) interactive table with hand shapes as input.

traditional mouse-based interaction. Here, I explore notable examples and discuss future research topics needed to advance organic user interfaces and make them more mainstream.

 

HOLOWALL

The table here outlines the features of organic HoloWall [ 5] is a camera-based interactive interaction, comparing them with the features of wall/table system that uses a combination of infrared traditional user interfaces. Even as the number of (IR) camera and array of IR lights installed behind novel interaction methods the wall (see Figure 1).

Traditional UI Organic UI

involving sensing tech- The camera captures the
Metaphor tools/stone skin/membrane
^{nologies has grown, such} Number of interaction points single plural or infinite ^{images on the back surface}
methods have been used _{State discrete (button On/Off) analog (continuous)} of the wall (illuminated by
mainly for some special Input position (x, y) shape the IR lights). An IR-
purpose (such as interac- Output (feedback) ^visual tactile and others blocking filter built into
tive art). Myron Krueger’s ^{I/O coupling separated unified} the LCD projector ensures
“Videoplace”(bubblegum. ^{Distance to target contact proximity} that the camera is not
parsons.edu) was an early ^{Purpose perform commands communication} affected by the projected
Place of interaction computer screen anywhere

example (early 1970s); in image. it, a video camera was used to capture a user’s body Since the rear-projection silhouette, and the full-body shape, not just finger panel is semi-opaque and positions, are used as input to the computer system. diffusive, the user’s hand shape in front of the screen In the next few years, as the cost of sensing and com- is not visible to the camera when the hand is far (more putation comes down, such organic interaction tech- than 30cm) from the screen. When the user moves a nologies are likely to be viable alternatives to finger close enough to the screen (10cm or less), the

Traditional GUI and organic interaction compared.