Game Development Reference
load ... In addition, specifically three-dimensional solutions are still quite rare and very
new. Application control in VE is therefore an open problem for which there is still no
totally satisfactory and accepted solution.
12.6.2 Text input
The symbols offer a description through a graphic representation of abstract ideas,
concepts, etc. Nowadays, the keyboard makes it possible to type a large amount of text
very fast. However, for now, effective methods of text input are nonexistent in virtual
environments (Sternberger &Bechmann, 2005). Unlike a classic desktop environment,
in 3 D the users are standing most of the time. They can move physically. There is little
surface area for installing a keyboard and its presence can disrupt the vision by hiding
a part of the scene. However, there is an entire set of tasks possible with the help
of text input: enter a file name, annotate objects or label them, change parameters,
communicate (email, blank tables, etc.), change the symbols as well (format a text, for
example), select one or several sections of a group of symbols. The question can be
summarised to know how to write a letter, enter a number, write an equation or save
a file. Some attempts were made temporarily: portable keyboards, gesture and voice
recognition and use of styluses for writing. We will now describe in detail the solutions
based on keyboards and manuscript writing.
In virtual reality, the main problems are related to the size of the keyboard. In fact,
when the user is standing, it is difficult to install it on a plane surface. Moreover, when
it is placed between the eyes and the screen or screens, it can hide a part of the scene.
On the other hand, computer keyboards are widely available and easy to use. There is
no learning needed to start using such keyboards. The idea here is to miniaturise these
peripherals, like portable computers, to be lighter and less bulky. The keys however
cannot be miniaturised below a certain size relative to the width of the fingers. When
the size of the device is relatively small, it becomes possible to place it in the palm of
one hand and press the keys with the other hand.
Even miniaturised keyboards generally have at least 50 keys. Rather than reducing
their size too much and making them difficult to handle, we can think of reducing the
number of keys. Why not combine them for creating all kinds of symbols, as in the
case of shortcuts (for example, “Ctrl
C'' for exiting an application under Linux).
Beyond virtual reality, other fields were faced with the problem of limited work space.
When it came to pressing just telephone numbers on mobile phones, only ten keys were
needed. With the emergence of instant messaging (SMS), mails, contacts and all other
applications requiring symbols, ten keys were not enough. To resolve this problem,
depending on the number of times you press a key, it is not the same number or
letter that appears. To help text entry, letters completing a word can be automatically
suggested, compared with a word dictionary. This technique is fast when the word is
known, but it is necessary to deactivate it when you wish to type a series of symbols
that have no immediate meaning.