RESEARCH ON VISION VARIABLE OF VIRTUAL TERRAIN ENVIRONMENT
Z.-Q. Wu, D.-M. Zhao
Surveying and Mapping Institute, Zhengzhou, China
With the further development of Virtual Reality Technique, its application in Cartology has got a fast advance. As a result, the 3-D map has become an important approach in the cognition of geo-spatial environment. As a graphical language of geo-spatial information expression, the design of 3-D map symbol system has a vital impact on the efficiency and effect of geo-spatial information transmission. Because the 3-D vision variables are basic elements of the design of 3-D map symbols, this paper firstly makes an analysis of the characteristics of virtual terrain environment and a comparison of 2-D and 3-D expression methods, then proposes the 3-D vision variables of virtual terrain environment, which includes a) the basic variables, such as shape, material, texture, attitude and so on, b) kinetic variables, such as duration time, frame velocity, sequence, and c) environment variables, such as view point, light, shade, fog, etc. Finally the applications of vision variables are discussed.