Generation of Appearance-Driven Low-Poly Textured Building Models with Differentiable Rendering

Abstract

Building models, characterized by their expansive scale and intricate assembly of components, often possess inherently complex geometric forms. Efficiently accessing such models on low-resource hardware such as netbooks and mobile devices remains a significant technical challenge. To address this issue, this paper proposes a novel appearance-driven building mesh simplification approach, building mesh simplification with differential rendering (BMS-DR), which is designed to yield visually consistent low-polygonal building meshes with enhanced textures. Upon receiving a building mesh model as input, the proposed method proceeds in a two-stage process: initially, an approximate building envelope is constructed through techniques including three-dimensional (3D) alpha-shaped hull construction, edge collapse, and UV unwrapping. Then, the geometry and texture of this envelope are refined through the application of differentiable rendering, forming the final low-polygon count model. For extensive evaluation, this paper introduces a novel Blinn–Phong function-based visual error metric and presents a data set comprising 134 distinct building mesh models exhibiting a variety of architectural styles. The experimental results demonstrated that BMS-DR performed well across all building models featuring apertures and recesses, consistently outperforming state-of-the-art methods in multiple visual quality metrics. This paper proposes a novel appearance-driven building mesh simplification approach named building mesh simplification with differential rendering (BMS-DR), which is designed to generate visually consistent low-polygonal building meshes with textures. Upon receiving a textured building mesh model issued from a modeling software and the required simplification rate as input, the proposed method is able to produce a corresponding low-polygon count model and associated textures in an offline manner. BMS-DR was evaluated with different visual error metrics and validated on a data set comprising 134 distinct building mesh models. BMS-DR can be integrated or built as a standalone package for BIM- or city information modeling (CIM)-related graphical applications, and it can bring performance gains when dealing with large textured mesh models or model groups.