融合轻量化网格与B-Rep的云架构CAD软件特征模型数据表示方法研究

云架构CAD软件对于推动工业技术云端软件化至关重要。当前云架构CAD软件受制于Web环境下数据传输与渲染效率，普遍采用数据表示局限于三角面片顶点与边结构几何与拓扑关系的轻量化网格模型，难以满足机械产品多特征语义耦合、约束驱动的参数化特征建模需求。本项目探索使轻量化网格与B-Rep融合且B-Rep约束下网格局部变形的云架构CAD软件特征模型数据表示方法。重点研究基于离散流形网格多微分特性耦合分析的边界形面辨识；以重构B-Rep拓扑关系驱动的保特征网格重划分，基于邻接形面干涉分析建立模型B-Rep拓扑关系并驱动特征语义识别与网格重划分；基于特征语义驱动且维持B-Rep拓扑关系的网格局部变形原理，建立边界约束的特征语义构形矢量参数计算模型，并提出参数驱动的网格局部变形算法。项目旨在突破基于Web的三维数字化建模基础核心技术瓶颈，对于我国研发自主可控的云架构CAD软件具有重要学术意义和应用价值。

Cloud CAD software is essential to promote the cloud softwareization of industrial technology. However, it is restricted by the efficiency of data transmission and rendering in the Web environment that most of the current cloud CAD softwares still use the lightweight triangular mesh, and the topological connection is limited to the relationship between the vertices and edges of the triangular faces, which are difficult to satisfy the requirements of the parametric 3D feature modeling of the mechanical products driven by the combination and constraint of the multi-features. This project explores the data representation method of feature model for cloud CAD software that integrating lightweight mesh with B-Rep and B-Rep constrained mesh local deformation. The boundary shape identification based on coupling analysis of multi-differential characteristics of discrete manifold mesh is studied. The feature-preserving remeshing method driven by reconstructing B-Rep topological relations is also studied, the topological relations of 3D mesh are built based on the interference analysis of adjacent surfaces, which promote the feature recognition and remeshing. The feature driven and B-Rep constrained mesh local deformation principle is also studied, a boundary constrained shape parameter calculation mode of feature is built, and a parameter driven local mesh deformation algorithm is proposed. Therefore, the research contributes to break through the core technology bottleneck of Web-based digital 3D modeling, which is of great academic and application significance for the research and development of independent and controllable cloud CAD software in China.