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2. SYSTEM OBJECTIVE 
The objective of the virtual community trials platform is to 
develop a Web3D based software platform for community 
services, community management and 3D visualization. 
We can carry through real-time dynamical walkthrough in the 
3D community scene, and accomplish community services and 
community management based on the 3D scene and 2D maps in 
virtual communities constructed with this software platform. 
3. SYSTEM ARCHITECTURE 
Distributed 3-tier architecture based on Internet is applied in the 
virtual community trials platform. It includes browser tier, Web 
server tier and application server tier. Figure | gives an overview 
of the system architecture of the virtual community trials 
platform. 
(1) Client-side is a general HTML browser (for example 
Microsoft Internet Explorer or Netscape Explorer) 
extended with Java applet, Java 3D, and VRML to 
support 2D and 3D graphics rendering and community 
function applications. 
(2) Web server-side utilizes operating system Windows 
NT4.0 and Service Pack3, and Web server software (such 
as Microsoft Internet Information Server, CGI, ASP and 
ISAPI). 
(3) As the core of the system, application server-side is the 
bottom of the system architecture. We use SQL server as 
the DBMS of the system on application server-side. The 
application server-side is of very importance in the 
system. It takes charge of data storage, organization, 
management and computation, the implementation of 
primary functions of the system, and coordinating with 
DBMS and various server components. 
Application server-side is developed with Java applications. It 
âccess Oracle database via JDBC. 
Three-dimensional rendering is enabled using the Java Plug-in 
and the Java 3D API on client-side. 
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rammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 
Java Applet 
JavaScript 
Java3D 
  
  
3 HTTP 
VRML 
HTML 
Client 
  
Server 
     
  
CGI ASP ISAPI 
Figure 1. System architecture of the virtual 
community trials platform 
4. COMMUNITY 3D MODELLING 
A virtual community model may include architectural structures, 
indoor detail objects (furniture, electrical appliances, and cables, 
etc.), and outdoor public devices (telegraph pole, trees, 
sculptures, roads, etc). 
3D reconstruction of a Community scene can be accomplished 
using 3D Studio MAX or Multigen. Based on the large-scale 
community map, the pipeline layout map, and the plans of 
primary buildings, we can construct a community 3D model and 
export it into VRML file format, and realize Web3D-based 
visualization via Java3D API.