Virtual Reality Model Created from Mobile Mapping Data as Interface to GIS
Krzysztof Gajdamowicz
Inst, of Geodesy and Photogrammetry
Royal Institute of Technology
Sweden
krzygajd@geomatics.kth.se
Commission III, Working Group 3
KEY WORDS: automated image processing, road inventory, VRML, hyperlinking.
ABSTRACT
Land vehicle based Mobile Mapping Systems (MMS) where GPS/INS are integrated and time tagged with CCD cameras are an
alternative to traditional tachymetric methods for mapping and inventory of roads and their surroundings. The analysis of MMS data
results in form of georeferenced images, geometric and semantic information about the objects in the image.
The World Wide Web (WWW) and Virtual Reality Modelling Language (VRML) allows to create a 3D virtual reality world from the
mobile mapping data. Such a 3D model is build from objects extracted from the georeferenced images. Capabilities of VRML browsers
allow not only for a visualisation and travelling in the model but also for dynamic hyperlinking with other types of databases, documents
and media sources.
This paper describes an approach to use Virtual Reality (VR) as interface to a GIS. The approach consists of several steps, i.e. data
acquisition, data analysis, creation of VR and hyperlinking to the other data sources. In the first step, the data acquisition, a short
introduction to the MMS will be given. In the second step, methods for data analysis, automated image processing as a tool for extraction
of geometric and semantic information will be presented. The third step includes an introduction to the VRML standard and methodology
for creating virtual symbolic representation of 3D world as captured by MMS. It describes how trees, buildings, and inventory objects
like road signs can be visualised and included into a 3D world. The last step describes hyperlinking of 3D cyberspace to the GIS and
other media sources.
1 INTRODUCTION
The Swedish National Road Administration (SNRA) is in the
process of transformation their existing Road Data Bank (RDB)
into the Swedish National Road Data Bank (SNRDB). The basic
structure of SNRDB will on the whole be inherited from an
existing Road data Bank, where the semantic, geometric, and
topologic information was related to nodes i.e. road crossing and
links. Some parts of SNRDB will have a form of multimedia
database. The idea is to combine and link existing CAD and raster
type of information related to roads and their surrounding.
Additionally, it is planned to link SNRDB with the other
databases like the National Land Survey Database or with the
local county information systems. This database requires a user
interface that will enable quick and easy access to the stored
information.
Rapid development in computer science offers high computing
power and powerful visualisation tools at a relatively low cost.
Existing 2-D GIS systems using traditional map representation of
spatial information do not meet the requirements of the market.
Urban and traffic planning, mining, oil exploration demands not
only maps and 2D images of buildings and streets but full 3D
CAD-raster representation. Such representation becomes
increasingly important (for example:Fritsch, 1996, Pasko and
Gruber 1996, Haala and Anders 1996, Kofler and Gruber, 1997,
Martin and Higgs 1997).
This paper approaches 3D symbolic representation of road
environment. The paper addresses following issues:
• the use of mobile mapping data for visualisation
purposes,
• modelling the physical environment by using symbolic
representation of 3D GIS objects,
• use of virtual reality, this is VRML tools for the
exploration of data from GIS tape databases.
