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2.1.4 Making of 3D according to designs directly in case of 
lacking plane figure An instance of this model 
2.2 Making of Drawings of Separate Parts of the Building 
The establishment of 3D models starts from the individual part 
reasonably in response to the property of ancient buildings that 
the whole body is occluded compactly through rabbets and 
mortises of each single part. 
A closed and independent 3D drawings, its shape, direction, 
size total consistent with its equivalent actual object reflect each 
model of the part. Such as Figure 1 is the 3D-drawing of Dou 
and Gong. 
Figure 1 
2.3 Assemble of One Floor 
In view of the fact that the wood ancient building is combined 
through rabbets and mortises of many sub-parts, it is usually 
divide into Columns, Dougong Layer, Roof frame, Eave Layer 
and Tile. The simulating process manipulated by AutoCAD 
must stick to the principle of compact assemble. Only in this 
way can the drawings reflect the exterior appearance and 
internal structure truly. After the 3D drawings of each part have 
been made, computers begin the organization layer by layer. 
Figure 2 shows the organization of part of the Dougong; Figure 
3 shows the organization of the whole body of Dougong; Figure 
4 shows the organization of the floor. 
  
  
Figure 4 
2.4 Assemble of the Whole 
With assemble of each floor finished, AutoCAD begins the 
assemble of the model of the whole building 
  
Figure 5 Surface model of pagoda 
3. COMPUTER SIMULATION 
Because ancient building is built of wood, lignification is one of 
its characteristic. In order to generate satisfactory and virtual 
realistic images of a timber building by the 3D computer 
simulation system, it needs to simulate the surface material of 
each component besides the establishment of correct model. 
Other component of ancient building is connected by mortises 
and tenons. During the mounting of ancient building, the order 
of mounting of different components is vitally important and 
restricted by their shapes and physical characteristics. Position 
of each component is measured by surveying. So those 
positions must be set up key frame during dynamic virtual 
simulation. 
3.1 Making Material 
The main task of generating material texture is to determine the 
color, texture and light and shade pattern of the material. The 
color of a material can be divided into three categories: 
ambient-----the color of the shading part of an object, 
diffuse----the color of an object under lighting, specular----the 
color of an object under strong lighting. 
Texture describes the natural characteristics of the surface of an 
object, it can be generated by a 2D random function 
fav)... Let N(u,o) denotes a normal distribution function p 
represents the mean value.orepresents the standard deviation!? ; 
Its value relays on pattern of material. Besides, the texture can 
be from a scanned image or generated by a graphic package. [2 
The following figures show the result. 
3.2 Moving Control Technic 
All the graphs and images generated up to now are stationary. 
The kernel of our project is dynamic virtual simulation, so 
computer animation technique is a must. Though many 
techniques of animation can be considered, the key-frame based 
method is adopted here. 
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