Researches on 3D Modeling of Geographic Elements and Integrating with Terrain Model

Abstract

Based on the basic theory of 3D expression of geographic elements and the concept, research framework and logic component of 3D map, the dynamic extension of Bergins visual variables in 3D visualization and the designing of 3D cartographic symbol are studied, to systematically analyze the 3D symbolic expression of geographic elements considering the terrain at different scales in 3D space by referring to the traditional cartographic expression theories and combining the characteristics of 3D environment. Then, the levels of detail in 3D point-shaped symbols and the deal of the relationship between point-shaped symbols and terrain model or other elements are discussed in the process of studying expression of point-shaped geographic elements in 3D space. Besides, the line-shaped elements are categorized into three types of elements, which are single-river, boundary and road, to study their symbolized expression based on terrain model in 3D environment respectively, and the multiple expression approach of the road at different scales is discussed emphatically in this part. Finally, the 3D expression of vegetation, soil and water treated as area elements is discussed respectively, according to geographic meaning and 3D modeling approaches of cartographic elements.