基于中轴表达的三维模型轮廓提取方法

三维网格模型的轮廓信息在网格检索、网格简化、网格重建中有着广泛应用。现有的轮廓提取方法较为复杂，需要分析和过滤网格模型的几何特征，计算量大且有时无法生成完整的轮廓信息。近年来，三维模型的中轴表达研究趋于成熟，在表达模型几何拓扑关系上有独特的优势。因此，提出了一种基于中轴表达的三维模型轮廓提取方法：首先提取三维模型的中轴表达信息，将中轴角点投影到三维模型表面；然后根据每个区域的拓扑关系选择适合的角点连接关系，将投影点连接形成模型区域轮廓；再针对投影过程中产生的误差进行分析和纠正；最后合并区域轮廓得到三维模型的完整轮廓。通过对多个模型数据库中代表性的三维网格模型进行实验和重建误 差比较，该方法的平均重建质量较现有方法约有 10%的提升，在重建质量和轮廓信息完整度方面优于现有方法。

3D model wireframe extraction method based on medial axis expression

The wireframe of 3D models is widely employed in mesh retrieval, mesh simplification, and mesh reconstruction. The complexity of the existent wireframe generation methods makes it necessary to analyze the geometric features of the mesh model and calculate the surface mesh of the model to obtain the wireframe. This entails a large amount of calculation and sometimes failures to complete the wireframe. To address the problems, a 3D model wireframe extraction method based on axis representation was proposed. Firstly, the axis representation information of the 3D model was extracted, and the corner points of the axis were projected onto the surface of the 3D model. Then, according to the topological relationship of each region, the suitable corner connection relationship was selected, and the projection points were connected to form the wireframe of the model region. After the connection operation, the errors in the projection process were analyzed and corrected. Finally, the region wireframes were merged to obtain the complete wireframe of the 3D model. Through experiments on and comparisons of reconstruction errors of representative 3D mesh models in several model databases, the average re-construction quality of the proposed method is about 10% higher than the three methods, outperforming the existing wireframe extraction methods in reconstruction quality and wireframe information integrity.