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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004
advantage of menus to select the data files from the database to
build a building that he/she likes.
e Customizing Roofs
The client side is also designed with a GUI (see Fig. 9) for
users to add various roofs to an existing building implemented
in the step above. Users are first required to choose what type
of roof they are interested in, and then input corresponding
parameters. Recently, we have designed nine types of roofs
described in Section 4.2. These roofs are stored in the roof
database. Users can call the roof ID, corresponding to the
VRML model ID, the specified roof will be automatically
added to the VRML model that users specified.
e Customizing Textures
The client side also has a designed GUI for users to stick
texture image onto the wall of an existing building created by
the VRML model. A texture image database, in which 200 real
wall texture images are stored, has been established, and
various texture images are displayed in the interface. Users first
choose a texture image with its identification (ID) that they are
interested in, and then input the texture image ID, and a
Building ID and a wall ID, the texture image will be
automatically stick to the corresponding wall.
4.3 Visualization
This server/client-based system has been implemented. This
system has functionality on pan, zoom, rotation, and visibility
analysis features. The texture data have been used for wall
features. We used this system to visualize Denver, CO, in
which 70 buildings have been created via client side (Fig. 10).
A client can pan, zoom in/out, and rotate the 3D model. With
the texture integration in 3D city modeling, it makes the 3D
visualization a much more real 3D representation.
3D Model Builder
zinkto adding roof page
Please inpui the 3D coordinates iu the following (Input the x,y coordinates of the
points of the cube; each line contains x, y coordinates and ended with pipeline ",";
The last line contains two hight coordinates, currently, remember leave coordinates
only one space hetween each other):
«i
Please choose the texture pictures for the cube, the sequence will be: TOP, BOTTOM,
FRONT, BACK, LEFT.SIDE, RIGHT-SIDE;
; Browse...
Ls |
: Loose |
Fae Browse...
fu 000 00m Browse...
ge _ Browse...
BE Browse...
also please specified the file name for the generated file
Run | Clear |
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UA
Fig. 8. Client front interface for generating building objects
Add Roof Page
Please input the 3D coordinates in the following (Input the x, y coordinates of the points
of the cube; each line contains x, y coordinates and ended with pipeline ","; The last
line contains two hight coordinates, currently, remember leave coordinates only one
space between each other):
Click the Ink for helping o
zio mput coerdinstes
Le
Please choose the texture pictures for the cube, the sequence will be: TOF, BOTTOM,
FRONT, BACK, LEFT-SIDE, RIGHT-SIDE;
| Browse...
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7 Browse...
| Browse. |
ae Browse... |
FE DE Browse... |
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a
Add Resident House Roof
Add Round Top
Add Four Angle To
Fig. 9. Client front end for making roof objects
5. CONCLUSIONS
This paper reports our research results of a project progress.
Based on the developed data structure, we implemented data
models using a relational database. Also, we built an automatic
tool for creating buildings and roofs, and sticking textures. By
storing 3D primitives into urban GIS databases, it is much
beneficial for VRML programming when these primitives are
retrieved from the GIS database. These 3D primitives appear at
a very high frequency in a 3D city model. The results from our
experiment demonstrated that this developed system is able to
display and visualize 3D city data in a web environment for
public accesses. Using the sidewall pictures taken from real
city buildings, we refilled the white walls of urban buildings for
a real appearance as seen in our real world cities. The player
provides several click buttons to enhance the effect and
position of visualization, including rotation, zoom, pan, seek,
etc. The users can easily view details of a specific building, or
an entire city in a moving 3D, or locate a specific building, and
so on. This technique will bring current 3D GIS city modeling
into a new era of development. Future work will implement
further details of the 3D city model, such as adding database-
querying ability, adding other geospatial objects, such as roads,
rivers, grasses, etc.
