Game Development Reference
Figure 12.30 Sensboard ® virtual keyboard system with pressure sensors, Sensboard Technologies AB
most used nowadays to write mails or to type out a report on the computer. However,
using a manuscript can also help in entering symbols on the computer-based tool.
One of the first uses was made on Palm. In fact, on PDAs, the idea was to provide a
handheld computer without a keyboard, but through which you can still write text or
other symbols. It is sufficient to use a stylus on a tactile screen by writing the letters of
a simplified alphabet (Graffiti 2 alphabet).
Other techniques were proposed, like Quikwriting by (Perlin et al., 1998). Like
Graffiti, this text entry system is based on using a stylus, generally of a PDA, but
here the stylus constantly remains in contact with the writing surface and the entire
sentence that the user enters is done in a single continuous gesture to increase the
writing speed. The alphabet is divided into zones around a central resting point. When
the user knows which letter corresponds to which movement, the alphabet no longer
needs to be displayed.
The Quikwrite writing system was transposed into a workbench type of virtual
environment (Grosjean & Coquillart, 2002). A handheld stylus makes writing on
a virtual surface possible. The stylus controls the movements of a pointer, which is
constrained in its movements on the two-dimensional writing surface.
Rather than using a PDA as a writing medium, some authors devised other surfaces
specifically dedicated for use in virtual reality. Poupyrev et al. (1998) proposed the
Virtual Notepad comprising a pen, a pressure-sensitive tablet and writing recognition
software. Here the user writes naturally, using the normal alphabet.
Application control and text input are still two relatively new interaction tasks in terms
of research. Clearly, the solutions proposed for the moment still do not satisfy users. For
application control, these solutions are strongly based on 2D interfaces that exist today
and that have largely proven themselves but do not essentially adapt very well in 3D.
The question of text input has cropped up again with the almost systematic absence
of a keyboard in immersive environments. There is every indication that unlike the
case of workstations, only a single solution will be accepted, however techniques vary
regarding the user, the application and the set-up ... This raises problems of selection
criteria of the solution to be implemented, when the significant need for assessments
is currently very rare.