The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008
point cloud consists of approximately 30 percent of these points,
the result (mean distance) without these points would be
reduced to less than 6 cm, which is an acceptable result.
In regions with overlapping datasets, the data had to be fused or
the overlaps had to be removed to avoid inconsistencies during
the meshing procedure. Here, the regions were combined by
removing the less accurate dataset in a particular region.
Therefore, the manual measurements were used as reference
data, the contour information was used to fill the occluded parts,
e.g. the upper parts of the shoulders.
5.1 Modelling of the surface
To generate a surface of the full object, the software Geomagic
Studio was used. First the automatic meshing function was
activated. This procedure was not successful, because the
implementation of the software could not handle the line-wise
structure of the dataset, with a high point density in line
direction and less density across the line. Some tests were done
to eliminate this inconvenience under preservation of the high
frequency information of the dataset. Nevertheless, the result
contained a number of holes and errors which had to be filled
and removed. The result is a consistent surface of the object,
see Figure 8.
Figure 8. Result of the 3D modelling of the full dataset using
Geomagic Studio
6. VISUALIZATION
The texture mapping was done using one image of the dataset B
with an in-house developed software. To visualize the extracted
data with around 600k triangles and to achieve a satisfying
result the open source software system Blender was used
(Blender, 2008). It is an open source 3D content creation suite,
available for all major operating systems under the GNU
General Public License. Among other features it can be used for
modelling, texture mapping, animation and rendering,
comparable with a commercial system, e.g. Maya (Autodesk).
The model data can be directly imported into the software.
Using this information the object can be visualized inside the
software in real-time and virtual reality models can be exported
in different formats (VRML, COLLADA, etc.). To generate
movies and high resolution images of the model different
additional steps are necessary. For example, different
illumination sources and camera positions, as well as the
camera path for the camera movement have to be defined in an
iterative procedure. These steps require, depending on the
experiences of the operator, some time to become familiar with.
Because of the lack of texture information in the occluded
regions, a not fully photorealistically textured model is
presented in Figure 9. In fact the missing texture was filled up
by artificial texture patterns.
Figure 9. Textured model of the Small Buddha
7. CONCLUSIONS
We have described the procedures that led to the 3D modelling
of the Small Buddha of Bamiyan, Afghanistan. We have used
two old amateur images of the destroyed Buddha figure itself,
some Sony Cybershot images for the modelling of the now
empty niche and a contour plot, generated from metric images
of a past photogrammetric campaign. The local topography
allowed only images to be taken with very skew angles.
Therefore many parts of the Buddha figure remained occluded
in the images and had to be reconstructed from the contour plot.
Given the difficult data configuration and low quality of the
primary data, automated methods of model generation do not
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