A tetrahedral mesh is used to perform finite element analysis (FEA) of surgical cuts in a medical simulator. Visualization of a tetrahedral mesh is an important challenge in the process of constructing a realistic simulator. As game engines become increasingly popular, many companies are beginning to develop their own engines, or using existing engines for software development. However, game engines such as Unity and Unreal do not accept volume mesh. What is more, during the cutting process, the topology of tetrahedral mesh will change, resulting in progressively difficult visualization. In this paper, we present a procedure to prepare a tetrahedral mesh for a surgery simulator. We will also show an example of cutting a sphere by deleting tetrahedral elements.