Automated Construction of Urban Terrain Models

Elements of urban terrain models such as streets, pavements, lawns, walls, and fences are fundamental for effective recognition and convincing appearance of virtual 3D cities and virtual 3D landscapes. These elements complement important other components such as 3D building models and 3D vegetation models. This paper introduces an object-oriented, rule-based and heuristic-based approach for modeling detailed virtual 3D terrains in an automated way. Terrain models are derived from 2D vector-based plans based on generation rules, which can be controlled by attributes assigned to 2D vector elements. The individual parts of the resulting urban terrain models are represented as “first-class” objects. These objects remain linked to the underlying 2D vector-based plan elements and, therefore, preserve data semantics and associated thematic information. With urban terrain models, we can achieve high-quality photorealistic 3D geovirtual environments and support interactive creation and manipulation. The automated construction represents a systematic solution for the bidirectional linkage of 2D plans and 3D geovirtual environments and overcomes cost-intensive CAD-based construction processes. The approach both simplifies the geometric construction of detailed urban terrain models and provides a seamless integration into traditional GIS-based workflows. The resulting 3D geovirtual environments are well suited for a variety of applications including urban and open-space planning, information systems for tourism and marketing, and navigation systems. As a case study, we demonstrate our approach applied to an urban development area of downtown Potsdam, Germany.