Abstract
¡§Web GIS¡¨ is a Geographic Information Systems¡]GIS¡^ operating on the Internet. Web GIS is very popular in the world now. This 2D web GIS can¡¦t display real world spatial information in three dimension. Virtual Reality (VR) is a fancy technology, which can display real world objects in 3D and is able to walk or fly through in this virtual world. Virtual Reality Modeling Language¡]VRML¡^can be used to construct local terrain and structures in 3D on the internet. In order to use geographic coordinates in the VRML, GeoVRML was developed for GIS purposes. This research tries to integrate the tools of 2D web GIS, VRML and GeoVRML into a 3D web GIS.
Concept of multi-view is used for this 3D web GIS, which combines a plan view, a model view and real view in a web page. The function of the plan view is to display 2D map and query attributes. The model view and real view are used to display 3D objects and link with database. However, the real view provides more object details in content and texture. This study tried to transform 2D polygons of the manmade structures into VRML and GeoVRML format without using specific software tools. The transformed 3D buildings are independent objects, which can link with database. The ways of creating terrain in GeoVRML are also discussed. A new node in the GeoVRML is suggested. A simple 3D spatial analysis is also explored.
Finally, the campus of our university ( National Sun Yat-sen University ) was used as an example for 3D web GIS. The orthophoto of the IKONOS satellite image and 40m digital terrain model data were used. The interaction among plan view, model view and real view were also designed. A database was successfully linked with model view and real view. The calculation of 3D spatial distance between two points was demonstrated. This 3D web GIS is proved to be a 3D GIS with capabilities of 3D data display, query and 3D spatial analysis.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0802101-145216 |
| Date | 02 August 2001 |
| Creators | Chen, Tai-hung |
| Contributors | Tian-Yuan Shih, Liang-Huei Lee, Yang-Chi Chang, Tien-Yin Chou, Shiahn-wern Shyue |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0802101-145216 |
| Rights | withheld, Copyright information available at source archive |
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