The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
not only the appearance but also the inner structure of timber- 
frame building needs to be presented to viewers. So 4 discrete 
LODs are used for an object; and their picked conditions and 
basic requirements are well considered. 
4.4 Engineering Supervision 
Based on our database and the knowledge gained in Mogao 
caves, we’ve perfectly performed the engineering supervision 
on the reconstruction work. Computer supervision uses the 
modem surveying technique to supervise the ancient-style 
building works and a 3-D model database of all wooden 
components has been established. Compared with this, the 
traditional method of supervision uses measuring rods, calipers, 
etc., requiring a large area, significant time, and a lot of work 
plus efforts while can only cover partial locations. In details, 
our work covers two parts, namely the Single-component 
Supervision and Assembly Supervision. 
Figure 8. Assembling Checking on Computer: when main hall 
was assembled on computer, a mistake of design 
was found. Two components, whose sizes are 
5.85m*0.29m*0.20m and 10.40m*0.48m*0.34m, 
were found unable to join into each other. 
4.5 Virtual Assembly 
The study on virtual assembly for some complex part benefits 
the quality supervising and technology planning a lot in the 
construction process, like making collision detection. Moreover, 
it contributes to research the art and technologies of building 
assembly, which can separate a complex building structure into 
different detail levels and provide a more clear view about it. 
Figure 9. Study on the archaic building art and technologies 
4.6 Virtual Roaming 
A virtual environment system is then built up based on the 
database with integrate 3D information about the timber-frame 
components. It owns three main characteristics. Firstly, it well 
represents the meaning of Chinese culture and arts of timber- 
frame buildings. Secondly, it can break through the limitation 
of special field by providing flexible Application Program 
Interface (API). Lastly, it can well meet the requirements of 
restoring ancient buildings and conserving historical documents 
(Du et al., 2006). Thus, it benefits the tourism a lot not only for 
providing a flexible viewpoint but also for replacing the real 
one just limited to its own place. 
(a) (b) 
Figure 10. (a) a snap of the 3D virtual scene; (b) a photo of the 
real scene (Du et al., 2006) 
4.7 Significance 
This transformation work brings up its significance in many 
ways. In the rebuilding process, the 3D data of the timber-frame 
components acquired in real time are used to make the scientific 
engineering supervision on its work and a real 3D data records 
have been taken for all the timber-frame components, therefore 
digitally recurring the constructing arts for timber-frame 
buildings of Tang Dynasty. And it also benefits us a lot in the 
future study about the archaic arts and crafts. Meanwhile, the 
exploitation for virtual building environment has provided new 
production and technical ways in the recovering, rebuilding, 
researching and protecting the timber-frame buildings. Thus, 
besides the real Chi Lin Nunnery, a 3D digitalized Chi Lin 
Nunnery will be improved to be a sensitive way in the future as 
it can last out forever for all human beings. It could always well 
keep the artistic and academic worth for further discovering, 
and we can easily hold this all as our eternal treasure. 
5. CONCLUSION AND FUTURE WORK 
5.1 Conclusion 
As is proved by facts and theories, Digital Cultural Heritage is 
the most effective way in researching, protecting and using of 
the cultural heritage. Under such circumstances as our cultural 
heritage is facing up with great difficulties, some essential 
methods to well protect our common fortune are in urgent need. 
Firstly, by the development of Laser Scanning and Virtual 
Reality, it is possible to build up a digital cultural heritage by 
using these tools to get accurate data and utilize it to keep any 
important information as well as to rebuild any mangled parts. 
Secondly, an on-line tourism can be set up to replace the real 
one for better and all-sided view, as well as let that real cultural 
heritage get less invisible damages. Lastly, based on the store of 
the multidimensional information about the cultural heritage in 
every detail, our database management system will offer 
convenient, agile and clipping information inquiring and 
searching. Our 3-D model owns more advantages, for example, 
the users can browse the breathing scene form multi-points, 
multi-paths and multi-angles alternant. Meanwhile, the multi 
language edition character , sound , real images and 3-D 
describes are also offered. 
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