6B-2-4 
whether on the right side or left side. As the 
result, we decided the direction of curve and 
added the polygon filled an opening. The road is 
modeled from the elements consist of real road 
such as centerline and sidewalk for using this 
calculation of coordinates and additional data. 
Example of representing the road is shown in 
Fig.5. This is the view from south to north in 
object area. 
Cross-product vector 
Fig.4 An opening of road model in corner. 
3. Evaluation and Conclusion 
As concerns representation of road, we can 
decrease the data compared with previous 
study. Regarding the road as a vector data 
makes us easy to calculate in adding the 
elevation value. The road through the mountain 
i 
should represent by considering with elevation 
value, but it can’t be done because we had not 
finished making the data of coordinates yet in 
the present stage. Using the additional data 
enabled us to represent centerline related with 
the road. As the result, we don’t have to plot 
these coordinates. The data of sidewalk is now 
under constructing. 
The problem that corner of next road sticks out 
is coming up when the elevation value is 
difficult from neighbor extremely. This is a 
peculiar problem in representing the object by 
3DCG. To solve this, we represent a corner by 
this method that search the coordinate of a part 
sticking out in corner, and divide the polygon 
consists of road into plural. 
REFERENCES 
[Yamamoto, 1997] Tatsuya Yamamoto, Tsukasa 
Hosomura and Yutaka Nyuuba, 1997 “ 3D 
Representation of Maps” Conference of JSPRS, 
pp.39-42 
Fig.5 Representation of road map.