Filling holes in LoD2 building models

TL;DR

This paper introduces a novel three-phase algorithm for filling holes in LoD2 building models that preserves original geometry and topological integrity, outperforming existing methods in producing complete, consistent meshes.

Contribution

The paper presents a new hole-filling algorithm for LoD2 building models that effectively manages topological errors without altering original geometry.

Findings

Superior performance in hole filling compared to related methods

Achieves more complete and geometrically consistent results

Slight trade-off in efficiency compared to existing approaches

Abstract

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