CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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4. 3D MODEL VISUALIZATION 
Different tools are available to display 3D models, shareware 
and commercial software, with or without real-time 
performance, interactive or not. Often the visualization of a 3D 
model is the only product of interest for the external world and 
remains the only possible contact with the model: therefore 
visualization packages are very useful and must provide very 
realistic views. 
The final 3D model generated with manual measurements is of 
rather big size and consists of ca 452 000 triangles. 
One of the few portable formats to interactively display a 3D 
model like the reconstructed Buddha statue is the VRML. With 
free packages like Cosmo Player or Vrweb we can display and 
navigate through the model or automatically fly along some 
predefined paths (Figure 13). The final VRML model of the 
Great Buddha, including also part of the surrounding rock, 
occupies ca 98 Mb. 
Figure 13: Visualization of the Buddha model with an Internet 
browser plug-in (Cosmo Player) 
Computer animation software (e.g. Maya) is generally used to 
create animations of 3D models. An example is presented in 
http://www.photogrammetry.ethz.ch/research/bamiyan/anim/bu 
ddha.mpg. 
Finally, a way to display attractive static views of 3D models is 
based on anaglyph images. An anaglyph mixes into one image 
a stereoscopic view using the complementarity of colours in the 
RGB channels. With coloured glasses, one can then filter the 
image and see the depth information of the model (Figure 15). 5 
5. PHYSICAL RECONSTRUCTION 
The 3D computer model that we generated with the manual 
procedure is used for a physical reconstruction of a scaled 
model of the Great Buddha. At the Institute of Machine Tools 
and Production, ETH Zurich, R.Zanini and J.Wirth have created 
a 1:200 model statue of the Great Buddha (Figure 14, right). 
The point cloud of the manual photogrammetric reconstruction 
is imported in a digitally programmed machine tool (Starrag 
NF100). The machine (Figure 14, left) works on polyurethane 
boxes and follows milling paths calculated directly from the 
point cloud. The physical model is created in three steps: (1) a 
roughing path, (2) a pre-smoothing path and (3) the final 
smoothing path. The time needed for preparing the production 
data was about 2 hours while the milling of the part itself was 
done in about 8 hours. 
Figure 14: The milling machine used for the physical 
reconstruction of the Bamiyan Buddha (left) and an image of 
the 1:200 model (right). 
6. CONCLUSIONS 
The computer reconstruction of the Great Buddha of Bamiyan, 
Afghanistan has been performed successfully using digital 
photogrammetric techniques. We have presented here the 
results of the 3D model, based on automated point cloud 
generation and manual measurements on three metric images. 
But we produced also accurate results using simple Internet and 
tourist images where typical photogrammetric information (as 
interior and exterior orientation parameters) was not available. 
While automated matching methods provide for dense point 
clouds, they fail to model the very fine details of the statue, e.g. 
the folds of the robe. Therefore, only manual measurements 
allowed to generate a 3D model accurate and complete enough 
to serve as the basis for a possible physical reconstruction in 
Bamiyan. 
We also reported how digital photogrammetry can be used to 
recover 3D models or technical documentation of historical 
monuments and sites. As next steps in our work we plan the 
following tasks: 
• Measurement of the cave surface (backside of the Buddha 
after destruction); 
• Generation of a photo-realistic 3D model of the cliffs and the 
extended vicinity; 
• Modeling of the frescos inside the Great Buddha cave; 
• Preparation of flyovers and animations. 
Before the physical reconstruction of the Great Buddha in 
Bamiyan can be performed the damaged and endangered cliffs 
around the Buddha cave have to be stabilized. This is currently 
discussed at UNESCO and in other international circles. 
A web site of the work has been established on our server and is 
available at 
http://www.photogrammetry.ethz.ch/research/bamiyan/ 
with more technical details and animations. 
ACKNOWLEDGEMENT 
The authors would like to thank Yuguang Li for the manual 
measurements on the metric images, Robert Zanini, Joachim 
Wirth and the Institute of Machine Tools Production, ETH 
Zurich, for the physical reconstruction of the statue at scale 
1:200, Tom Bilson, Courtauld Institute of Art, London, for