A Terrain Feature-Based Method For 3D Geographic Information Visualization

As the rapid development of Chinese society and economy, three-dimensional geographical information systems (GIS) are being more and more widely used in urban planning, architecture, spatial decision. However, how to visualize 3D geographic information with high quality is one of the key technology issues.In the study of three-dimensional visualization, the speed of modeling and the level of model reality are two important measures of quality. At present, the visualization methods fall in three types:DEM and image based; regular geometry and 2D GIS based; three-dimensional model based. The three types of methods focus on different aspects. Under different conditions, while the three-dimensional geographical scene can be established in all three methods, the level of detail and the modeling speed with each method vary considerably.This thesis has the following objectives:(1) To introduce concepts and metrics of the development of a 3D geographic information system, and to explain and compare the three types of existing modeling methods and model representation technologies;(2) To propose a new approach that visualizes geographic information in 3D based on feature types, such as trees, buildings, water, vegetation, and roads;(3) To analyse 2D GIS data of a virtual campus for the establishment of a two-dimensional digital map, and then to simulate height and texture data of some ground objects. The 3D virtual campus, which supports Free Roam, is established using the 3D geographic information visualization tool.