The Optimization And Realization Of Techniques For Digital Relief Shading

The digital relief shading is the main method that express undulation change of geography appearance on the 2D flat surface, consumers has more need about expressive force, art and agility of relief shading along with the application become more extensive. How can the relief shading figure various topography logically and true, having well expression and achieving high effect is chief problem that the relief shading face.This paper set out from peculiarity of relief shading itself, aims at lack of digital relief shading technique, combines with analysis of geography characteristic, research and realizes optimization for relief shading technique. The main contents include:1. Discussing the rationale of relief shading and technique of digital relief shading. Expatiating three keystones that are the theory for geometric optics, halftone change and aerial perspective. Summarizing different method for showing geography that aims at different geomorphic type. Researching the related technique and making process of digital relief shading.2. Studying the conception, classification and function for topographic parameter, discussing arithmetic of distilling parameters that relate to relief shading. This paper analyses the different arithmetic for slope and aspect particularly, then brings forward Third Order Difference has good applicability in relief shading. Analyzing and summarizing the characteristic and variational rule of topographic parameters for different geomorphic type though experimentation.3. Expatiating the need of researching optimization for relief shading technique, brings forward the method of researching. The main matters include putting out optimization range and assuring the change of color tone naturally by using arithmetic of distilling point and line of geography characteristic, the buffer arithmetic interpolation algorithm; discussing lambert illumination model and model based on aspect, analyzing the difference and excellence themselves, bringing forward the choice for illumination model with relief shading; Choosing the reasonable light source though statistics and analysis of topographic parameter, concluding the four instances may appear about choosing light source; analyzing the meaning, function and application instances of modulating for color tone, bringing forward the method that compartmentalizes flat area and modulates tone of flat area by using slope and disposing yawp.4. Though using techniques researching in optimizing relief shading, establishing the system of making relief shading by programmer, introducing the function of system and the basic process for making relief shading by using system in brief.