This paper presents a new algorithm for filling holes in Level of Detail 2 (LoD2) building mesh models, addressing the challenges posed by geometric inaccuracies and topological errors. Unlike traditional methods that often alter the original geometric structure or impose stringent input requirements, our approach preserves the integrity of the original model while effectively managing a range of topological errors. The algorithm operates in three distinct phases: (1) pre-processing, which addresses topological errors and identifies pseudo-holes; (2) detecting and extracting complete border rings of holes; and (3) remeshing, aimed at reconstructing the complete geometric surface. Our method demonstrates superior performance compared to related work in filling holes in building mesh models, achieving both uniform local geometry around the holes and structural completeness. Comparative experiments with established methods demonstrate our algorithm's effectiveness in delivering more complete and geometrically consistent hole-filling results, albeit with a slight trade-off in efficiency. The paper also identifies challenges in handling certain complex scenarios and outlines future directions for research, including the pursuit of a comprehensive repair goal for LoD2 models to achieve watertight 2-manifold models with correctly oriented normals. Our source code is available at https://github.com/tudelft3d/Automatic-Repair-of-LoD2-Building-Models.git

翻译：本文提出了一种用于填充细节层次2（LoD2）建筑网格模型中孔洞的新算法，旨在解决几何不精确性和拓扑错误带来的挑战。与常改变原始几何结构或施加严格输入要求的传统方法不同，我们的方法在有效处理多种拓扑错误的同时，保持了原始模型的完整性。该算法包含三个不同阶段：（1）预处理阶段，处理拓扑错误并识别伪孔洞；（2）检测并提取孔洞的完整边界环；（3）网格重构阶段，旨在重建完整的几何表面。与相关工作中的建筑网格模型孔洞填充方法相比，我们的方法在孔洞周围实现了均匀的局部几何结构以及结构完整性，展现出更优越的性能。与现有方法的对比实验表明，该算法能生成更完整且几何一致的孔洞填充结果，尽管在效率上略有权衡。本文还指出了处理某些复杂场景的挑战，并概述了未来研究方向，包括实现LoD2模型的全面修复目标——获得具有正确法线朝向的防水二维流形模型。我们的源代码可通过以下链接获取：https://github.com/tudelft3d/Automatic-Repair-of-LoD2-Building-Models.git