Construction and Visualization of Levels of Detail for High-Resolution LiDAR-Derived Digital Outcrop Models

High-resolution LiDAR-derived 3D digital outcrop models are essential for detailed geological analysis, but their massive data volumes often exceed the rendering and memory capacities of standard computer systems, posing significant visualization challenges. Although Level of Detail (LOD) techniques are well-established in GIS and computer graphics, they are not directly suitable for the elongated, cliff-face morphology of typical outcrops. This paper presents an automated method for constructing and visualizing LOD models specifically tailored to high-resolution LiDAR outcrops. The workflow begins by segmenting the monolithic model based on texture coverage, followed by building an adaptive LOD tile pyramid for each segment using a pseudo-quadtree approach. A feature-preserving Quadric Error Metric (QEM) simplification algorithm, incorporating boundary freezing and fallback strategies, is employed to retain critical geological structures while significantly reducing geometric complexity. For visualization, a dynamic multi-scale loading and rendering mechanism is implemented using an LOD index with the OpenSceneGraph (OSG) engine. Results demonstrate that the proposed method effectively overcomes the bottleneck of rendering massive outcrop models, enabling smooth, interactive visualization and providing a robust foundation for multi-scale geological interpretation.