【摘要】 提出一种新型包围盒 ,该包围盒由 12个 4 5°面组成 ,且包容原裁剪窗体 ,则落在包围盒外的线段必然在裁剪窗体之外 ;同时引入三维到二维投影 ,进行二次编码舍弃窗外线段 ;最后通过基于包围盒编码分区的几何变换完成裁剪过程 常规包围盒一次编码、新型包围盒二次编码、基于编码分区的几何变换求交这三个步骤构成了基于包围盒编码的三维线段裁剪新算法 实验结果表明 ,文中算法提高了裁剪效率并具有很好的稳定性更多还原

【Abstract】 The clipping process is realized in three steps First, Cohen Sutherland encoding is used to totally reject or accept line segments Then, a new regular polyhedron with 12 square faces all inclined at 45° to horizontal plane and circumscribing the first clipping window is introduced If a line segment is totally out of the box, it must be out of the window The second encoding system is applied to reject more lines through projecting the new box and lines from 3D to 2D Finally, the clipping process is completed by finding the intersection points of lines with window boundaries, the partition encoding is simplified through geometric transformation Experimental results show that the new algorithm is robust and more efficient than classic ones更多还原