上海交通大学学报(自然版) ›› 2013, Vol. 47 ›› Issue (12): 1813-1817.

• 自动化技术、计算机技术 •    下一篇

一种基于点表面的尖锐特征绘制方法

戴春锋,顾力栩   

  1. (上海交通大学Med-X研究院, 上海 200030)
     
  • 收稿日期:2013-03-13 出版日期:2013-12-28 发布日期:2013-12-28
  • 基金资助:

    国家自然科学基金重大项目(61190124)

A Rendering Method for Point-Based Surfaces with Sharp Features

DAI Chunfeng,GU Lixu
  

  1. (Med-X Institute, Shanghai Jiaotong University,  Shanghai  200030, China)
  • Received:2013-03-13 Online:2013-12-28 Published:2013-12-28

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.
 
 

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

Abstract:

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 handle 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 clipping edges of every point.
 

Key words: point-based graphics, splatting, sharp feature, point-and-edge model, clipping

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