Abstract: NURBS is one very important tool for complex volume design. The Boolean operations among complex NURBS volumes are difficult. A NURBS volume could be voxelized into a series of triangles, or planar convex quadrangles. By calculating the intersection points between DEXEL rays and triangles, or quadrangles, this NURBS volume is dexelized. This procedure is called dexelization. Under the same DEXEL model space, Boolean operations among dexelized complex NURBS volumes are linear, simple and easy. Under Java2.0 and Java3D, this algorithm is tested and one mechanical part design example is given.

摘要： NURBS曲面与NURBS体造型技术是目前复杂体造型的重要工具，但复杂体之间的布尔运算求交困难。将NURBS曲面围成的体与NURBS体体素化（VOXEL化）为由一系列平面凸四边形或三角形表示的体，通过DEXEL射线组群与四边形或三角形求交，实现NURBS体的DEXEL化。在同一DEXEL模型空间实现复杂NURBS体之间布尔运算,所有运算是线性的。该方法可推广到在逆向工程中生成的由三角面表示的体。在Java2.0与Java3D环境下编程实现并验证了该算法，给出了一个机械零件设计实例。