基于退化多边形求交的多面体虚拟壳模型重构

三维模型的重建和表示是计算机图形和计算机视觉中一个重要的领域,其广泛应用于自动识别,工业自动化设计以及虚拟场景的重建。文中实现一个从照片序列重建三维物体多面体模型的系统,使用由轮廓恢复形体(SFS),通过经由轮廓光锥相交得到包围物体的虚拟壳。在系统中采用的共极线几何和增量运算把所有的三维的相交计算投射到二维平面的退化多边形求交来降低相交计算的复杂度。与传统多面体虚拟壳重构相比,算法有以下几点改进:在图像平面以退化多边形组织投影锥体和物体轮廓的交集,把任意锥面与物体轮廓的交集归一到一个退化多边形;基于退化多边形的二维平面上多边形快速相交算法。通过这些改进可以减少虚拟壳的生成时间并有助于实时绘制的实现。

Polyhedral Visual Hulls Reconstruction Based on Degenerated-Polygon-Intersection

The3-D model reconstruction and representation are important in the computer graphics and computer vision.The3-D model is essential to the recognition,automatic design and visual scene reconstruction.This paper represents a system which can reconstruct the3-D polyhedral visual hull from a series of photos by the intersection of cones.It employs epipolar geometry and incremental calculation to project3-D intersections onto the2-D planes to avoid the complexity in the intersection.Compared with the traditional methods,it has following improvements:use degenerated polygon to organize intersected polygon;a fast intersection algorithm of polygons on the cone face based on degenerated polygons,which is consistent between the continuous polygons and the discontinuous ones.With these improvements,it can reduce the time used in reconstruction of visual hulls and help to realize real-time rendering.