Research And Implementation Of Automatic Generation Algorithm Of The Control Mesh In Mesh Editing

Mesh editing can be widely applied in computer animation,3D game, virtualsimulation and geometric modeling. Because of mesh editing method based on barycentriccoordinates has flexible operation and efficient feature, it attract wide attention formscholars. In most cases we need control mesh called cage that model surrounded toestablish the barycentric coordinates. Usually, the cage is made by a personal hand-job ora complex calculation. So it was inefficient, time-consuming and professional. We focuson proposing a relatively simple method about cage generation as a result.Firstly, because of the complexity of triangular mesh models, we use edge collapsemethod to simplify the mesh. Then we calculate the normal of facets on the mesh to getthe normal of vertices and move the point along the normal to get a point set outsidemodel.Secondly, because of the computational complexity of point set generation, we needto create a bounding box for the model and voxelize it to get the point set. For each facetof the model, we also calculate its bounding box and extend the bounding box along theaxis.Thirdly, we establish a mapping relationship among voxels, bounding boxes andpoint set, and calculate the distance between point in point set and facet on the modelthrough the mapping relationship to delete some point to avoid self-intersecting. Then wecan reconstruct the cage by point set.Finally, based on VS2010, we use C++language, and CGAL implement the auto-matic generation of the cage for a certain size. Experiment result show: our method cansimplifies the complex operational requirements of manual control mesh generation andreduce the time of the normal control mesh generation and meet the needs of barycentriccoordinates in mesh editing.