Biomedical Engineering Reference
In-Depth Information
the benefit of such interaction in a distributed floorspace. This approach can be seen
as an alternative to desktop computer interfaces for navigating geospatial data, and
may be particularly suitable for situations in which an immersive display is involved
or in which users' hands are occupied with other tasks.
We developed these interactive techniques for exploring geospatial information
by navigating with a floor-based map interface, presented via the multitouch floor
surface. The application was developed with the user interface framework presented
above. As participants navigated to specified locations using the map, via one of the
foot-floor interaction techniques, the images of the streets for the locations visited
were presented in real time via the wall surfaces whenever applicable. The available
data was acquired from existing internet-based mapping applications from Google
and Microsoft.
The interaction techniques investigated included a “pivot” interface, which uses
relative foot position as a navigational input, a “magic tape” interface that uses
absolute foot position within the workspace, a “sliding” interface that allowed users
to virtually push themselves within the mapping interface, and a “classic” approach
using virtual buttons and sliders to provide a comparison with a more conventional
user interface paradigm. Additional gestures allowed participants to control the zoom
level of the map.
Classic Interface
The Classic interface transposes the basic design used for spatial navigation in
mouse-based applications to the setting of floor-based interaction. Four buttons in
a cross arrangement control position and a discrete-valued slider provides control
over the zoom level. The discrete slider levels match those used for the whole body
gestures in the subsequent interfaces. In the Pivot mode, users establish a pivot point
by standing still for a short period. Placing one foot outside of the pivot area, indicated
by a circle around the feet, pans in the direction specified as the vector from the pivot
center to the outside foot. The participant can, at any time, exit the pivot area and
establish a new one elsewhere. In the Sliding interface, a user first establishes a pivot
point by standing still for a short period. Then, by placing one foot outside the pivot
area and using sliding or dragging gestures, akin to touch-screen scroll on an iPhone,
the user can pan the map (Figs.
17.14
,
17.15
,
17.16
,
17.17
).
The Magic Tape interface was inspired by the work of Cirio et al. and takes
advantage of the larger floor surface by employing an interaction paradigm based on
absolute foot position. This metaphor allows users to navigate freely in the center
of the floor space, without altering the displayed map contents. However, when
participants walk past the boundary region of the floor surface, the map pans in a
direction designated by the user's position. The farther the user strays from the center,
the greater the panning speed.
Gestures: Crouch or Jump to Zoom
Unlike the direct-manipulation inspired control actions described above, gestures
are recognized to allow temporally extended body movements, such as jumping,
