切开外部物体的表面去显示里面的物体，在可视化研究领域具有广泛的应用前景。以前采用计算机图形学的方法是用透明显示，或者要求切割的形状是规则的。本文重点研究了任意形状的切割，首先用户在2维的空间中定义一个形状，然后将该形状投影到外面3维物体上再做切割，该算法还解决了连界上的一些锯齿形问题，实验结果表明该算法是有效的。

Cutting away part of a 3D outer surface to show some interior objects hidden beneath it can play an important role in visualization and virtual reality. Previous methods have mainly aimed at showing the interior objects, and the shape of the hole has been considerably less important. In this paper, we propose a novel approach to cutting a specific hole in a surface. The user first defines the required shape on the surface; the algorithm then superimposes the shape on the surface and implements the cutaway. Jittering problems associated with the boundary generated by the above steps are resolved and experimental results demonstrate the efficiency of the algorithm.