Research On Relief Visualization And Generation Of Hill-Shading Maps

For years, two subjects—cartography and geographical information system have always been sharing their interests in this hot topic, relief visualization, and it is also an issue which urgently demands our gpnlogists to improve. In this paper, both history and significance of relief visualization are summarized, and the concept of relief visualization is discussed in great detail as well.Terrain visualization and hill-shading are two main topics in this paper, whose principles are similar, both referring to the visualization of digital elevation model. The difference between these two principles is that: the former is three-dimensional visualization of digital elevation model, while the latter is planar representation of digital elevation model. Therefore, the author makes emphasis on the latter. Much is discussed in detail in this paper, including geometry optical principles and color principles of hill-shading, methods for terrain modeling in computer-assisted hill- shading, principles of lamp-house models, principles of three-dimensional rendering and so on. Based on above study, rules for hill-shading color making and rules for using hill-shading lighting sources are also summarized.In the last part of this paper, Relief Visualization and the Generation of Hill-Shading Maps system are introduced, and key technologies involved in this system. Moreover, rules summarized in above are exemplified and enriched through this system, and based on these rules and corresponding principles the system is also improved. Lastly, some ideas on future work are proposed based on the system.