Boundary Identification and Triangulation of STL Model

In order to identify the border of STL model with open border, topology structure of STL model was reconstructed using half edge data structure. On this basis, border segments of STL model can be identified by a process of edge traversing. Then constrained Delaunay triangulation with Steiner point insertion was used to triangulate the border regions of STL model. In this way, STL model was closed and it provides necessary foundation to further finite element mesh generation.