In many 3D applications, building models in polygon-soup representation are commonly used for the purposes of visualization, for example, in movies and games. Their appearances are fine, however geometry-wise, they may have limited information of connectivity and may have internal intersections between their parts. Therefore, they are not well-suited to be directly used in 3D geospatial applications, which usually require geometric analysis. For an input building model in polygon-soup representation, we propose a novel appearance-driven approach to interactively convert it to a two-manifold model, which is more well-suited for 3D geospatial applications. In addition, the level of detail (LOD) can be controlled interactively during the conversion. Because a model in polygon-soup representation is not well-suited for geometric analysis, the main idea of the proposed method is extracting the visual appearance of the input building model and utilizing it to facilitate the conversion and LODs generation. The silhouettes are extracted and used to identify the features of the building. After this, according to the locations of these features, horizontal cross-sections are generated. We then connect two adjacent horizontal cross-sections to reconstruct the building. We control the LOD by processing the features on the silhouettes and horizontal cross-sections using a 2D approach. We also propose facilitating the conversion and LOD control by integrating a variety of rasterization methods. The results of our experiments demonstrate the effectiveness of our method.

在许多3D应用程序中，通常以多边形汤的形式构建模型用于可视化，例如在电影和游戏中。它们的外观很好，但是从几何角度看，它们的连通性信息有限，并且零件之间可能存在内部相交。因此，它们不适合直接用于通常需要几何分析的3D地理空间应用程序中。对于多边形汤表示形式的输入建筑模型，我们提出了一种新颖的外观驱动方法，以交互方式将其转换为两流形模型，该模型更适合3D地理空间应用。另外，可以在转换过程中以交互方式控制详细程度（LOD）。由于多边形汤表示形式的模型不适用于几何分析，所提出方法的主要思想是提取输入建筑模型的视觉外观，并利用它来促进转换和LOD生成。提取轮廓并将其用于识别建筑物的特征。之后，根据这些特征的位置，生成水平横截面。然后，我们连接两个相邻的水平横截面以重建建筑物。我们通过使用2D方法处理轮廓和水平横截面上的特征来控制LOD。我们还建议通过集成各种光栅化方法来促进转换和LOD控制。我们的实验结果证明了我们方法的有效性。