Figure 6 simulation picture Figure 7 simulation picture 
of Dou-gong of Dou-gong layer(planform) 
  
Figure 8 simulation picture Figure 9 simulation picture 
of Dou-gong layer(upward) of bell tower 
3.2.1Key-frame Technic 
The most popular computer animation technique is based on 
key-frame technique. The core of this technique is to fix the 
so-called key-frames, and then let 3DS MAX software system 
to interpolate to generate those between key-frames. The B 
spline function is used [2.3] 
  
  
key frame 
Insert frame among key frame 
Figure 10 movie of key frame 
slowdown 
quic k ss 0 N 
slow t invariable 
invarrabic 
M 
^" 
“ i 
acceierate 
Figure 11 slope and speed of movement 
After the attribute values of key frame is given, they will be 
stored in a structure named curve node and will be controlled by 
the node. These curves are defined by the attribute data of the 
key frame, the speed of the animation then can be adjusted by 
the tangent of a curve. 
Usually, (Fig 11)the gradient of a curve indicated the speed of 
an object. Steep curve indicates high speed, while flat for slow. 
Consequently, horizontal curve indicates the object stopped. 
Pictures(Fig.12) is build-up process of timber component 
4 CONCLUSIONS 
Computer simulation is a hot research field in computer science. 
It provides a novel environment for people to explore macro- 
world and micro-world. It is also the superb stage of 
multi-media technology. However, to implement this technique 
perfectly, obstacles are on the way. Both speed and processing 
capacity of computer hardware are limited, and price of high 
quality display equipment is also excessively expensive. On the 
other hand, expense of software development is also out of 
tolerance. Many works are still waiting people to do. 
ACKNOWLEGEMENTS: 
This study is supported by the National Natural Science 
Foundation of China (Project No, 40023004, 40071068). 
REFERENCES: 
1. Xu Miaozhong Zhu Yixuan, 1998, Computer-Based 
Simulation and Quality Control for Building, Working 
Group V/5, ISPRS, pp. 252-258. 
2. Huang XingYuan, 1999, Virtual Reality Tachnic and 
Application, Science Publishing. 
3. Sun JiaGuang Yang ChangGui, 1994, Computer Graphics, 
TsingHua university press. 
4. Jiang Wanshou, Zhu Yixuan, 1999, The Making of High 
Precision Orthoimage of Ancient Buildings, Proceedings of 
the 20th Asia conference on Remote Sensing, 
pp.1081-1086. 
5. Zhu Yixuan, Chen Zhiyong, 2000, The Process Of Making 
3D-vector Scenograph Of Ancient Building With Large 
Quantities Of Data, Proceedings of XIXth ISPRS congress 
Amsterdam 2000, pp.568-572. 
6. Ma Bingjian, 1995, Chinese Ancient Timber Structure 
Construction Techniques, Science Publishing. 
  
Figure 12 movie of a series of Dou-gong 
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