一种基于点表面的尖锐特征绘制方法  

A Rendering Method for Point-Based Surfaces with Sharp Features

作　　者：戴春锋 顾力栩[1] 

机构地区：[1]上海交通大学Med-X研究院,上海200030

出　　处：《上海交通大学学报》2013年第12期1813-1817,1822,共6页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金重大项目(61190124)

摘　　要：针对抛雪球算法不能很好地处理尖锐特征这一问题,对已有的点边混合模型进行了改进,提出了一种通过射线法判断点与裁剪区域关系的裁剪算法,并给出了基于该算法的绘制策略.该算法能够处理多种复杂裁剪情况,包括复杂多边形及非闭合区域,减少了表面边界对表面点采样率的约束,有效避免了原有绘制方法中复杂的增加采样率的预处理过程,简化了整个绘制流程.通过对比不同模型的绘制速度,得出裁剪算法对绘制速度的影响主要取决于每个像素点的裁剪边数.The splatting algorithm has difficulty in rendering sharp features. To solve this problem, the point-and-edge model was used and improved. A novel clipping algorithm, which used a ray-based method to decide the relative position between points and clipping areas, was proposed. This algorithm could han- dle various clipping, reduce the restrictions on the sampling rate of surface points caused by the boundery of the surface, avoid a complicated upsampling preprocessing step and simplify the rendering of the model. A comparison of different models indicates that the rendering speed is mainly affected by the average clip- ping edges of every point.

关 键 词：基于点的图形学 抛雪球法 尖锐特征 点边混合模型 裁剪 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]