Footprint-profile sweep surface: A flexible method for realtime generation and rendering of massive urban buildings

Generation of a large-scale city requires a significant amount of manual work and computation to process massive location information and model building geometry with multi-level of details. Normally, an urban city is heavily built-up with different architectural building patterns across extensively and topographically varied landscapes. In this paper, we introduce Footprint-Profile Sweep Surfaces (FPSS), a flexible and computationally efficient approach for realtime generation and rendering of massive urban buildings in a heavily built-up city. A solid constituting an urban building is represented as an instance of FPSS and is generated by sweeping a footprint along a profile with specific parameters. We present two forms of FPSS: super FPSS to address the shapes from architecture design and poly FPSS to address the shapes from imported GIS data. We make use of hardware tessellation to allow dynamic LOD according to view distance. A special scaling-translation-rotation displacement performed on the simplified profile is proposed to support detail generation. Experimental results show that realtime performance can be achieved using our approach to generate varied styles of urban buildings. Even inexperienced users are able to generate a building group quickly in their own style based on FPSS.