A Collaborative Virtual Geographic Environment:

Design and Development

Jianhua Gong, Chinese Academy of Sciences, China

Hui Lin, The Chinese University of Hong Kong, Hong Kong

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Abstract

A collaborative virtual geographic environment (CVGE) is a 3-D, distributed,and graphical world representing and simulating geographic phenomena and processes to enable geographically distributed users to explore geoproblems and theories and generate hypotheses, and to support geomodel building and validation and collaborative ecological planning. This chapter reports an approach to establishing a CVGE across the Internet, and its application to the collaborative planning of silt dam systems in watersheds through the integration of distributed virtual environments, geographical information systems (GIS), planning models of dam systems, and geocollaboration. The chapter addresses the conceptual and system frameworks of the distributed CVGE, and the 3-D modeling of virtual geographic environments and virtual collaborative studios in addition to the mediated tools for collaboration, such as streaming media based communication, shared whiteboards for text input and graphics drawing, and text-based dialogue. In a case study of the Qiu-Yuan-Gou watershed, Suide County, Shanxi Province, China, a prototype system is designed and developed with Java, Java3D, and VRML. The complete dam systems in the Qiu-Yuan-Gou watershed represent a typical example model of a massive silt dam construction project on the Loess Plateau. The study employs the example model of the watershed to explore the methodologies of collaborative spatial planning of silt dam systems. Using the prototype system, participants

can implement communication with each other via media tools, mainly in the virtual collaborative studio, and 3-D editing of shared dams, calculation of topographic properties, and ideal spatial distribution of dam systems in virtual geographic environment.

Introduction

Geographic environments are open, huge complex systems in which most complicated geoproblems, such as ecologic planning, sustainable urban development, evaluation of large geographic projects, disaster forecasting and early warning, emergency response and process, and ecologic security need to be collaboratively explored and solved by a group of people. Meanwhile, the rapid development of information and communication technologies facilitates the potential to invent many tools to support collaboration, with computer-supported cooperative work (CSCW) becoming an important research field (MacEachren, 2001; Mandviwalla & Khan, 1999). In the GIScience community, the limitations of current geographic information systems only designed for individuals, and the resultant increase in interest in geocollaboration is evidenced by the growing body of work on group decision support systems, public participation GIS, collaborative GIS, and collaborative geovisualization (Batty, Didge, Doyle, & Smith, 1998; Benko, Ishak, & Feiner, 2003; Cheng, Hu, & Ma, 2003; Craig, Harris, & Weiner, 2002; Densham, Armstrong, & Kemp, 1995; Jankowski & Nyerges, 2001; MacEachren & Brewer, 2004). This chapter will focus on the design and implementation of technologies for geocollaboration from the perspective of distributed virtual geographic environments.  

The rest of the chapter is organized as follows. In section 2, work related to geocollaboration, with a special emphasis on distributed-virtual environments, is presented through a discussion of relationships with the online community, networked visualization, and Internet/virtual GIS. Section 3 elaborates the design of the conceptual and system framework of collaborative virtual geographic environments. Section 4 presents a prototype system of CVGE, and a case study of the dam systems planning in the Jiu-Yuan-Gou watershed. The last two sections conclude with a discussion of future research trends.

Background and Related Works

Geocollaboration can be defined as a group of people working together in both the same or differing geographical locations and time to accomplish geotasks or to solve complex geoproblems. The study of geocollaboration involves diverse aspects ranging from participants and organization to mediated tools, geoproblem contexts, and supportive environments. From the viewpoint of geocollaboration supportive mediation technologies, this chapter highlights distributed virtual environments supporting different place/same time geocollaboration. Distributed virtual environment technology works to establish distributed, 3-D environments allowing geographicly distributed users to meet and interact virtually with objects and processes, and collaborate with other users in 3-D worlds on the Web (Gong & Lin, 2000; Normand, 1999). In recent years, distributed virtual environments have drawn increasing interest in academic and industrial communities (Blaxxun, 2005; Dykes, Moore, & Wood, 1999; Hibbard, 1998; Oliveira, Shen, & Georganas, 2000; Singhal & Zyda, 1999 ).

From the perspective of online communities, originating from the online textbased or voice-based chat rooms such as the famous Muds (multiuser dungeons) and Tencent OICQ in China, distributed virtual environments are now used to create online, 3-D communities for conducting a variety of activities such as chatting, game playing, forming clubs, virtual house building, and shopping in the virtual mall (Cooper, 2000; OICQ, 2005). Figure 1 illustrates a snapshot of Cybertown, a well-known 3-D Internet community (Cybertown, 2005). In Figure 1, online users are represented as 3-D avatars that can navigate in 3-D worlds and chat with other users. From the perspective of networked computer graphics integrated with CAD and visualization technology, distributed virtual environments are applied to the building and distribution of CAD or visualization environments for collaborative designing or visual data interpretation. Figure 2 shows a distributed CAD design environment called DMUConference (Tecoplan, 2001). In the DMUConference environment, geographically distributed designers can meet virtually and discuss the design of cars.

Applications and importance of virtual reality/virtual environment technology have increasingly drawn attention in the GIScience, modern cartography, and geographic sciences communities (Batty et al. 1998; Faust, 1995; Gong & Lin 2000; Gore 1998; Van Maren & Germs, 2000; Verbree, Maren, Germs, Jansen, & Kraak, 1999). Much effort has been directed towards the integration of the traditional GIS, geographical application models, AutoCAD, and distributed tools such as ActiveX, VRML, Java, and Java3D to construct distributed virtual geoenvironments (GeoVE) on the Internet. Using Java and Java3D, Hibbard et al. (Hibbard, Rueden, Emmerson, Rink, Glowacki, Whittaker, Murray, Fulker, & Anderson ,2005) designed and developed a VisAD system to create applications

that enable many users to implement the visualization of a shared set of numerical geodata and geocomputations. Based on Geometrek’s DeepMatrix 1.1, an existing multiuser virtual environment, Manoharan et al. (Manoharan, Taylor, & Gardiner, 2002) established a collaborative urban planning prototype system to assist shared analysis of urban planning proposals by visualization and interaction with spatial data. MacEachren et al. (MacEachren, Edsall, Haug, Baxter, Otto, Masters, Fuhrmann, & Qian,1999, MacEachren, Cai, Sharma, Rauschert, Brewer, Bolelli, Shaparenko, Fuhrmann, & Wang, 2005) address geospatial virtual environments (GeoVE) and dialogue-assisted visual environments focusing on visual representation, exploratory interaction, visually-enabled dialogue, and team/group collaboration in the context of geovisualization. From the perspective

of geography, Gong and Lin (2000) present the concept of virtual geographic environments, and define a virtual geographic environment as a human-centered environment that represents and simulates geographic environments (physical and human environments), and allows distributed multiusers to implement exploratory geospatial analysis, geocomputation, and geovisualization, and to conduct collaborative work for supporting design and decision. The building of virtual geographic environments needs to integrate such technologies as GIS, distributed virtual environments, and CSCW. The major aim of the virtual geographic environment is to allow traditional geographers to carry out their research work on comprehensive and complex geoproblems in an efficient and innovative way on a data- and graphics-driven integrated platform.

In this chapter, we employ theories and technologies of collaboration and distributed virtual geographic environments to first explore the features and framework of CVGE, and then carry out the design and development of the CVGE system.