Research On Approaches To Filling Complex Holes In Triangular Mesh Models

With the rapid development of the global manufacturing industry,the product development cycle has become a core element for companies to improve their market competitiveness and to pursue the production of high-quality products in the shortest time at the lowest cost.The application of reverse engineering technology in product development has greatly reduced the product development cycle,and effectively improved the market competitiveness and production efficiency of enterprises.The triangular mesh model is the most widely used model in the reverse engineering.However,due to many factors,there are holes in the triangular mesh.The extraction and filling of holes are very important preliminary work.Especially for the repair of complex holes,there are still many problems and challenges.The identification and extraction of holes is the preliminary work of holes filling.Faced with a mesh model containing a large amount of data,two efficient search methods for complex holes objects are proposed based on the wing-based data structure and the face-based data structure,respectively.While searching for hole objects,the presented methods can realize the automatic splitting of non-manifold holes and the identification and extraction of island holes.In addition,a method for automatically matching the hole boundary and the island boundary is proposed.Aiming at complex holes in the triangular mesh models with sharp curvature changes and across multiple feature surfaces,a hole segmentation method based on ridge fitting is proposed.First,detect the sudden change of curvature on the boundary of the hole,identify the feature line of the surrounding area of the hole.Then the identified feature lines are matched,and fitted as segmenting lines of the hole.Finally,the segmenting lines are discretized into vertex chains.As a result,the complex hole boundary segmented into a set of simple holes,which can use a simple hole filling algorithm to complete the hole repair.In addition,based on the complex hole segmentation,this paper proposes a method for repairing complex island holes.First,the feature plane of the island area is established.The island mesh and the segmenting lines are projected onto the feature plane,and the island area is divided into sub-islands and the sub-islands are paired with the sub-holes.Finally,the feature-based projection method is used to repair the island holes.The holes filling method for triangular mesh models proposed in this paper is realized by Visual C ++ and OpenGL programming.The experimental results show that the method has good filling effect on holes with sharp curvature changes and complex island holes,and can maintain the details of the original models.