Ostrava, 25. 1. 2005
GEOVISULIZATION!
new player in geoinformatic team
or
old cartography in a new coat?
Vít Voženílek
Scientific visualization
• Visualization capitalizes on the strength of human
perceptual abilities.
– The human brain has an impressive capacity for the understanding
and assimilation of graphically presented information.
– Visualization tools provide the means to filter and explore rapidly
growing quantities of spatial data, perceive patterns that may be
apparent at one resolution but may otherwise remains hidden at other
resolutions, transform surface data to simulate 3D and develop
representations of temporally changing landscapes unlimited by
constraints of a single-view map
– The graphic representations stimulate visual thinking and facilitate
geographic problem-solving.
• Current visualization technology provides a full range of
HW and SW from static 2D plots, to interactive 3D images
allowing the user to interact on a human scale.
• Scientific visualization is „a tool for both interpreting image
data fed into a computer and for generating images for
complex multidimensional data sets“.
– The ideas of VISC are slowly permeating the geographical and
cartographic communities, particularly among those practitioners
engaged in computer-based work.
The nature of visualisation
• three dimensional model of
human-map interaction space
by MacEachren
– that defines what might be
considered prototypes for
visualization and
communication
• from map use that is private
(tailored to an individual) to
public (designed for a wide
audience),
• map use that is directed toward
revealing unknowns
(exploration) versus presenting
knowns (presentation),
• map use that has high
interaction versus low
interaction.
The continuum of visualization
from public to private use
• although the categories, static images, interactive visualization and
mental visualization are depicted as separate, the boundaries
between them are fuzzy and the range is actually continuous and
interactive
• the main uses of the different categories, although the boundaries
are also fuzzy
Cartography and visualisation
• graphical presentation of information has a long history
(some of the earliest graphical presentations are maps)
• cartography has had and to have an important role to play
in the graphical presentation of geospatial information
• Fairbairn defined cartographic representation „as the
transformation that takes place when information is depicted in a way
that can be perceived, encouraging the senses to exploit the spatial
structure of the portrayal as it is interpreted. These representations
are usually graphical, but may also be haptic or audible, or involve
elements that mix other senses with sight“.
• the most critical issues in cartographic research:
–
–
–
–
–
the characteristics of the data to be handled
the visual design and the user interface
the representation purpose
user interaction with dynamic representations
the changing technology to support new forms of representation
(how representations can be accessed and enhanced).
The spatial media may have four types of
media functions (according to cognition science)
• function of demonstration
– by using media to give a realistic picture (demonstrate the idea,
object or landscape) with photos, videos or virtual reality
• function of putting into context
– to put the detailed information into a bigger context, like an
overview of the area (for spatial context), or sounds that are related
to a particular area may help the user to identify and position the
given information
• function of construction
– It is related to the creation of complex mental models by the user
– abstract media of pre-prepared information is best suited for this
function, such as graphs, diagrams or abstract layers
• function of motivation
– to stimulate on the user interest and attention
– this can be achieved with animations, interactive objects, e.g.
interactive fly-overs are a typical example for this function
3D visualization
• All communication between the readers of an image and
the makers of an image now take place on a twodimensional surface.
– Escaping this flatland is the essential task of 3D geovisualisation
– for all the interesting worlds (physical, biological, imaginary, human)
that people seek to understand are inevitably and happily
multivariate in nature
• 3D visualization provides an effective way of presenting
large amounts of complex information to a wide audience,
including those with no GIS or mapping experience.
• The 3D visualization systems were designed taking into
consideration cognitive principles and are able to integrate
high quality mapping of the current situation, 3D
representations of the future and (geo)multimedia
(regarding real world information).
DiBisae's model of the role of maps in
scientific visualization
• Cartographers need to
direct attention to the role
of maps at the early
(private) stages of
scientific research where
maps and map-based
tools are used to facilitate
data sifting and
exploration of extremely
large data sets
3D visualization in GIS
with SiteBuilder 3D, plug-in for ArcGIS
with ESRI´s 3D Analyst
3D visualization in GIS
with Autodesk Map 3D 2005
3D visualization in GIS
with Precision Lightworks Nverse Photo, a plug-in for
Autodesk VIZ or Discreet 3ds max
3D visualization in GIS
with software from NGRAIN Corporation
Below are five important advantages to
digital map:
• Real-time redesign
– Digital maps can be redesigned by the user base and specific need. This
advantage is very important to expert users who know a significant amount
about the thematic content of the map and the how the digital system works.
• Identity
– The ability to identify an object on the map provides a robust interaction with
graphic elements not available to paper maps.
• Query
– The ability to query information related to the map form is an exciting
advantage. By developing a query environment through the map, map
readers can reduce the complexity of the spatial information and focus only
on selected elements.
• Links to non-spatial databases
– The link to data allows digital maps to access additional information not
currently shown on the map.
• Spatial analysis
– The final advantage of the digital map is the ability for the user to perform
both simple and complex spatial analysis tasks such as buffer, overlay and
others. The ability to perform analysis makes the digital map a process
based analytical tool.
The paper map has five properties that
would benefit the digital map:
• Cartographic fidelity
– printed map is printed using high standards for print resolution and color quality
– for the computer this is limited to the technical specification of the visual output
device
• Display size
– maps can be print on paper exceeding the size of video devices
• Power consumption
– paper maps do not need to use power unless artificial light is needed to view it
• Portability
– it means a function of size, weight and power
– computers are getting smaller PDA, tablet PC and others, but increasing
portability causes more problems for cartographic fidelity and display size
• End user cost
– digital maps are not cheaper than paper!
– one can download a route map with four clicks of the mouse and not pay a fee
for the map itself. But the information on the Internet is not free. One must have
a computer, software and Internet providing to access a world wide web site
– some of costs are ongoing and deferred through much usage, but still the cost
for digital maps are expensive compared to a road atlas with a cost of each
map being pennies. So the cost to the end users is still high for digital maps
vit.vozenilek@upol.cz