利用改进扫描线法的面曝光快速成形的掩模图形

Using the improved scan line algorithm to generate the mask image in mask projection stereo-lithography system

在对掩模图形的生成机理进行研究的基础上,提出用扫描线法生成基于STL数据模型的掩模.针对大数据量的轮廓边扫描效率较低的问题,改进传统的扫描算法:重新定义边数据结构,将边表分为3个动态区间以存储相应的边,从而实现了在无需判断截面曝光域与非曝光的情况下,直接借助边表填充截面轮廓,快速生成具有多层嵌套关系的排模图形.该方法可避免构建与维护活动边表,简化扫描线算法的实现过程,同时可解决传统算法较难解决的奇点问题.

On the basis of extensive research about the generation theory of mask image,a method of using the scan line algorithm to generate the mask image based on the STL model in mask projection stereo-lithography system is presented.In view of low scan conversion efficiency of great data nested crosssection contours,the most commonly used scan line algorithm is improved：the edge data structure is redefined,and the edge table is divided into three dynamic intervals so that it can store corresponding edges.The scan conversion in the edge table can be achieved directly without establishing and maintaining the active edge table by the improved algorithm,and multiple nested contour loops can be filled rapidly without judging the properties of both inside and outside of every contour.Moreover,the problem of odd point problems can be efficiently dealt with.