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.