International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004 
    
   
   
  
   
   
    
  
   
   
   
    
   
  
  
  
   
   
    
  
  
  
   
    
     
  
  
  
  
  
  
  
DEL 
Terrain 
hn is Road Surfaces 
Road Center Greenbelt 
y, Wuhan Roadbed 
  
  
Road Ditch 
Road Counterfort 
  
  
Street Lamp 
  
  
Guidepost 
I 
  
Road Auxiliaries ELE 
Road Fencine 
Road Outline Sign 
Gas Station 
  
  
  
  
ed in many 
such as the Repair Bav 
  
  
  
  
  
  
  
  
  
The Modelling of Road Elements 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
ut forward s vers Dinine-room 
ition al => | The Buildings Je v 
mic multi- [oilet 
id effective Restaurant or Hotel 
se between | 
/ Park 
geographic | c= > [ Traffic Sign ]—— Road Drive Wav Line 
ch can turn | 
er, but also | Skv 
-efficiency | E— | Road Scene J EN Road. Tree 
| Grass 
  
  
; Figure 1. The Modelling of Road Elements 
to Improve 
iciency of : ; ; : : 
Octree model (Li, 1994), the integrated TIN and Octree model 
| (Shi, 1996), and the integrated TEN and Octree model (Li, E n 
1996); An object-oriented 3D GIS model (Yang Bisheng, 2002). Sa | 
Due to the road complication, there are many researchers put d bk 
ondition of forward lots of road data model and road structure. The road 
jad three- | flight is applied to express the road in the MultiGen Creator, in 
which if the road center line is set, the road will be created with 
standard road flight, the road surface is on the same height, the 
higher outside in the road crankle can't be expressed (Figure 2). 
A based on TIN partition model (Figure 3) is put forward to 
  
  
  
  
  
  
  
   
  
] center express the road (Sun Min, 2000). MultiGen Creator and based 
auxiliaries on TIN partition model can't express the road ditch, roadbed, 
line sign), road counterfort, and road auxiliaries etc. Figure 3. The road expressed by based on TIN partition model 
TOOm, 
ve way 2.3 Transect-based Road Model 
o on | 
Based on the study of the road model, the author put forward to 
a new road model to express the three-dimensional road in the 
computer. This model is based on the road transect, and the road 
is composited by many transects. The simplest road that is 
defined a road flight is composited by two transects, the road 
standard transect and defines are expressed in figure 4. 
mportant to | 
:hers of the 
one lots of | 
  
  
, a surface- 100 
ta | , 
mu zt à, 97..| 96 ; it 
50 iS vr: mal Tia 
| is. 13 I2. 14 
Figure 4. The Road standard transect and the road elements sig1.