ISPRS, Vol-34, Part 2W2, "Dynamic and Multi-Dimensional GIS”, Bangkok, May 23-25, 2001
several different images. This may be caused, for example, by
overlapping in the image mosaic generated by the camera, or
images taken from radically different views. There is also the
case where the camera has zoomed to get very high-resolution
data for a particularly important scene feature.
The availability of multiple texture sources for a single triangle
necessitates additional consideration. To decide which texture
source to use, we make use of the label map obtained during
hidden texture removal to provide the number of pixels in the
corresponding image that would be used to texture map any
given model triangle. All that is required is to sum the number
of instances of the triangle in the label map. This is done for
each triangle in every image and the image contributing the
largest number of pixels is used as the texture source. Such
that all those triangles sharing a common texture source are
grouped together.
Figure9 Texture mapping Result of Kyoto Train way Station
area
This work was finished by using Softimage|3D system. We
summary the main procedure is shown as follows(The result is
shown in Figure9):
• Surface segmentation for 2D texture mapping
• Generation of texture images by 2D affined
transformation
• Imputing texture images into Softimage|3D (TIFF to
PIC)
• Object oriented texture mapping based on
Softimage|3D
• Defining parameters for animation (color, camera,
light, material and so on)
• Visualization 3D virtual environments based on
Softimage|3D
• Output 3D results from Softimage|3D to TIFF images
3.6 Spatial Object Editing
After generation of 3D visual models or VR environments, we
should check the result based on exiting air photos of maps.
The task was finished base on the 3D editing environment of
Softimage|3D system. We should make the procedure for
sequentially highlighting 3D objects on a 2D base map and
image environment. The checking are semi-automatically done
by operator’s mouse processing. If we find the problem, we can
lock this object and modify it based on different 3D editing
tools.
3.7 Problem and Future Application Plan
According to our research result, we can find the following
problems that should make feather research in the future:
1) . The accuracy and density of laser range data
• The distance between random points is too far.
• Some site has no 3D data
• The accuracy is lower for extraction buildings with
high densities
2) . Improving the accuracy of object structures
• Improving the accuracy of object structures by using
3D data from multi-sources (mobile mapping, laser
range data from ground stations)
• Automated 3D feature extraction based on
knowledge bases and existing GIS
3) . Improving the accuracy of texture images
• Getting the orientation parameters by using digital
photogrammetry system
• Generation of ortho-photos for accurately texture
mapping
3.8 Application Plan
Our future works can be summarized as follows:
1) . Multi-sensor integration
• Airborne laser range data processing
• Ground laser range data processing
• Mobile mapping data processing
• Integration
2) . Improvement of digital photogrammetry system for
structure feature extraction
• Automated extraction of roads and buildings based
on DSM and laser range data
• Automated extraction of roads and buildings based
on existing GIS
• 3D environment for editing 3D spatial objects
3) . 3D GIS and virtual environment
• Generation of 3D spatial information systems
• Generation of virtual environments for visualization
and simulation
• Different applications
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