中文摘要：

与历史无关造型技术已成为三维CAD系统令人关注的研究方向之一，对于带有拓扑和几何信息的轻量化模型进行直接编辑是该技术的典型应用。鉴于B-rep模型的变化实际上表现为其内部拓扑和几何的变化，本文基于拓扑结构保持不变的前提，对三维模型一个或多个几何面改变时其相邻边界的几何一致性更新方法进行了研究。提出并分析了适合于多面体模型的边界几何求交方法，并进一步给出了融入模型重构的综合算法。通过实例验证了上述方法的可行性。

英文摘要：

The direct editing of a lightweight 3D model with topological and geometrical information is a typical application of the history-independent modeling technique to a 3D CAD system. Considering that the boundary representation （B-rep） model changes with the variation of its inner topology and geometry and assuming that its topological structure does not change, the paper studied the local geometrical updating method for updating the geometrical consistency of its adjacent boundaries when its one or more geometric faces are adjusted. Then it analyzed the boundary geometrical intersection method suitable for a polyhedral model, and further presented a hybrid algorithm that integrates model reconstruction. An example was also given to verify the feasibility of the above-mentioned methods.