An effective terrain model for web‐based 3D geographic information systems

Abstract

SUMMARYThe needs of three-dimensional implementation and WWW-based geographic information systems are increasing. In this paper, we propose a flexible and efficient VRML-based terrain model. In the proposed model, by placing side by side the terrain models (tiles) of fixed size in 3D space, the simplification of display range change, the utilization of a caring mechanism, and the attachment of an automatic changeover mechanism for the level of detail of the model will become possible. Each tile is modeled by combining multiple grid models, and the useless polygons in the sea and lakes are curtailed. Moreover, we propose an automatic changeover mechanism of the level of detail of the model, which regenerates the shape features of the terrain objects such as square and flat. Furthermore, for curtailing the transmitted data, we also propose a method for automatically generating simplified models from the detailed model on WWW terminal side. Finally, the effectiveness of the proposed model is shown by 3D spatial navigation experiments using automatic viewpoint motion.

A review on 3D terrain visualization of GIS data: techniques and software

“…Araya et al (36) proposed a flexible and efficient VRML-based terrain model placing side by side terrain models (tiles) of fixed size in 3D space. As the simplification of the display range changes, an automatic changeover mechanism for the LOD of the model becomes possible.…”

Online 3D Terrain Visualization: A Comparison of Three Different GIS Software

“…The VRML technology has been used by many researchers for developing online visualizing for large 3D terrain data. They are using many different technique such as Level of Details (LOD), tiles technique, progressive technique, and selective visualization [6,7,8,9,10] Shiau, Shiau, & Liang [11] has proposed a new system for creating the 3D environment by combining the Digital Terrain Model and SPOT images of GIS with the weather simulation of the particular system in a networking environment. In order to make the system run in real time several accelerating schemes have been used.…”