International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004
4. APPLICATIONS AND RESULTS
The following cultural heritage projects were carried out using
the DILAS 3D GIS in order to assess its suitability and to gain
valuable information for further developments and
investigations.
4.1 3D model of the castle of Wildenstein, BL (Switzerland)
A recent project at FHBB addressed the acquisition and
modelling of the castle of Wildenstein, BL (Switzerland). This
castle is the only preserved height-castle in this region. The
tower of the castle was built around 1293. The other parts of the
castle were built later around 1693.
Figure 4: Castle of Wildenstein, BL (Switzerland)
As shown in the photograph above the acquisition and
modelling of the castle was very difficult due to its exposed
location and complex form. Thus, a range of technologies were
used for the surveying of the castle. The exterior hull of the
castle, for example, was surveyed by means of helicopter-based
digital close-range photogrammetry using a Nikon D100
camera. The interior of the castle was surveyed using reflector-
less tachymetry and terrestrial laser scanning. A precise
geodetic control network was established to tie these different
surveys to a common reference system. The comparison
between the two methods revealed some interesting results.
While laser scanning is unbeatable in terms of data acquisition
rate, it proved that current laser scanning processing software is
still ill suited to the modelling and construction of irregular 3D
objects and that operators typically reverted to the combination
of tachymetry and CAD construction. The integrated result of
these surveys was a 3D CAD model of the castle of
Wildenstein.
The DILAS 3D GIS was subsequently used to manage the 3D
model of the castle.
Building Room
ID A ID
Name Room type
Year of Construction Floor
Comments Comments
3D Geometry FK1 |Building Reference
2D Boundary 3D Geometry
2D Boundary
Vegetation : Building structures Digital terrain model Orthoimages
ID ID Name Name
Description Description Description Description
3D Geometry 30 Geometry Resolution Resolution
2D Boundary 2D Boundary Height data Image data
2D Boundary 2D Boundary
Figure 5: Data model of the castle of Wildenstein
The data model for this application 1s shown in Figure 5. In this
case the data model is relatively simple and consists of
buildings and their rooms. However, the objects themselves can
be highly complex and can consist of a lot of geometry
elements with - different semantics (e.g. wooden facade or
concrete ground etc.). To manage this so called element
thematic it was necessary to attach thematic attributes to all
geometry elements. This can be done using XML-based import
rules which, for example, assign element attributes based on
CAD levels before storing the 3d objects in the database.
The project revealed a number of advantages of the 3D GIS
over the CAD file-based solution. One was the possibility to
selectively load one or more rooms or building parts from the
database based on different predicates such as floor number,
room type or building material. Another advantage was the
multi-user support which allowed several different teams of
students to simultaneously work on the same 3D model.
Following the generation of the complete 3D model in DILAS
which also included the digital elevation model and the
orthoimagery of the area, an interactive 3D scene was created
(Figure 6). This 3D scene can be displayed with the viewer
technology G-VISTA.
; Figure 6: 3D model of the castle of Wildenstein, BL
(Switzerland)
G-VISTA is a high-performance 3D viewing technology which
enables the interactive visualisation of very large 3D landscapes
— either from CD/DVD or via the Web. The web-based capabi-
lity significantly extends the range of users and applications for
such cultural heritage projects. In our case the 3D model is not
only used for the digital preservation of the castle of
Wildenstein but also for the presentation and exploitation of
this important historical site via the Internet, e.g. for
educational purposes.
4.0 3D reconstruction of the roman city of Augusta
Raurica (Switzerland)
Augusta Raurica was a roman city ten kilometres east of Basel.
The city was inhabited by some 20'000 people in the first
centuries A.D. Many monuments are well preserved and the
historic site attracts more than 120'000 visitors annually
(www.augustaraurica.ch).
The aim of first diploma thesis at the FHBB was to create a
realistic virtual 3D model of the modern city of Augst, which
was partially built on top of the ruins of Augusta Raurica. The
base data consisted of aerial imagery and ground planes of the
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