Geography Reference
In-Depth Information
1 Introduction
The need for ''true 3D'' is backed up by previous studies carried out by the first
author in the 1970 and 1980s, which show that more than 60 % of all users of
topographic or hiking maps are not able to derive relief information spontaneously.
The
participants
were
members
of
alpine
climbing
courses
with
academic
educations.
''True'' 3D? Is there also an ''untrue'' or ''false'' or ''pseudo'' 3D? Yes, there is.
Pseudo-3D depictions are visualised perspective-monoscopically on planar media,
e.g. on a monitor screen. They are not autostereoscopic. True-3D visualisations
can be parallax-3D or full-3D. While parallax-3D geovisualisations only use
selective bi- and monocular depth cues, full-3D geovisualisations use all bi- and
monocular depth cues (Buchroithner
2001
). Thus, the authors define any scene
which can be stereoscopically seen, but not only because of the perspective, as
''true-3D''. In this sense, physical landscape embodiments can also be considered
''true-3D''. The (only) difference is that in the latter instance we apply natural
stereovision (solid models), in the other case we use a special way of artificial
stereovision. Hence, one might also talk about displays with touchable reliefs and
planar (''flat'') true-3D displays. The essential thing is the provision of two distinct
stereomates to the viewer's eyes, whether created ''artificially'' or not.
Stereoscopic displays can be analogue, these are the so-called hardcopy displays
or they can be digital, the softcopy displays. Furthermore, they can be divided into
non-autostereoscopic and autostereoscopic displays. Non-autostereoscopic displays
require glasses or similar viewing aids to provide a spatial impression, but autos-
tereoscopic displays allow a spontaneous spatial perception without any additional
viewing means (see Knust and Buchroithner
2012
). There exist single-user displays
for only one user at a time and multi-user displays. With the latter multiple users
can perceive a spatial impression simultaneously. The users of stereoscopic
displays can be head-tracked, meaning if the viewer moves in front of the display
the stereomates are tracked to keep the spatial impression. Furthermore, the ability
to visualise 3D images can be switchable or not. Switchable displays can also be
used on a normal 2D screen.
By means of an overview of the historical development and technical status
Buchroithner (
2007
) tried to explain the importance of three-dimensionality in
cartography. Both physical landscape models as well as pseudo-3D and true-3D
autostereoscopic visualisations on planar displays were investigated. Besides
reasons for the advantages and necessities for true-3D representations, the author
also gave a short preview on the interactive and dynamic possibilities of future 3D
visualisation.
In a recent publication Buchroithner and Habermann
2010
introduced the term
relief aesthetics, a term which still needs to be defined and investigated in more
detail and which has a close connection with relief intensity (German: Relief-
energie, see Bill and Zehner
2001
), a parameter which might also allow the
quantification of the aesthetic value of the relief of a landscape. In conjunction
