An Implementation of 3D GIS on web
3. Automatic Translation Interface
In order to confirm the practicable of method with our research, we integrated our study result to program the Automatic Translation Interface(ATI), the ATI structure is as follows:
Fig 3. ATI structure
When 2D GIS File is improved into ATI, we can set translation area, the ATI will analyze nodes of all 2D object and translate into VRML format. In the same time with translation, ATI will be exported every 2D object's attribute data into database, and add a link on every 3D VRML object.
4.Example
For testing ATI, we made of choice the first campus of Feng Chia University for our experiment. We imported the 2D campus file into ATI(see. Fig4) and the result is very perfect. ATI exported a VRML file that the size is only 50 KB and every building is independent.
Fig 4. Fist campus in ATI
User can connect to our 3D GIS web site(http://rand.gis.fcu.edu.tw/3DGIS) to visit this VRML scene and query every building attribute data. This result proves our method of this study is practicable.
Fig 5. First campus VRML scene
V.Conclusion
This research resolve the bottleneck of 3D GIS on web, i.e. transfer 2D GIS data to VRML and keep their attribute data concurrently, this is just a beginning, and there are several problems should be discussed:
- It decreases the speed of browsing VRML scene when VRML scene has a large size, binary VRML format will be a good solution for decreasing the presently ASCII VRML format.
- How to query a spatial object not only by mouse click, but also by object attribute is next phase to research.
- The result shows the
building objects by cube, i.e., the 3D shape of
a building is based on its 2D shape, and extrude
with its attribute related to its height, it's a
simple way to display a spatial object, but also
ignore the real figuration of itself, how to
present a spatial object with its original
figuration is worth to study in the field of 3D
GIS on web.
References
- Bo Huang, Hui Lin,1999.
GeoVR: a web-based tool for virtual reality
presentation from 2D GIS data, Computers and
Geosciences 2591999), p1167-p1175.
