Automatic Generation of 3D Building Models with Efficient Solar Photovoltaic Generation

To facilitate public involvement for sustainable development, 3D models simulating real or near future cities using 3D Computer Graphics (CG) can be of great use. 3D city models are important in environmentally friendly urban planning that will use solar photovoltaic (PV) generation. However, enormous time and labour has to be consumed to create these 3D models using 3D modelling software such as 3ds Max or SketchUp. In order to automate laborious steps, this paper proposes a Geographic Information System (GIS) and CG integrated system that automatically generates 3D building models based on building polygons or building footprints on digital maps, which show most building polygons’ edges meet at right angles (orthogonal polygon). A complicated orthogonal polygon can be partitioned into a set of rectangles. The proposed integrated system partitions orthogonal building polygons into a set of rectangles and places rectangular roofs and box-shaped building bodies onto these rectangles. In this paper, for placing solar panels on a hipped roof, the structure of an ordinary hipped roof that is made up of two triangular roof boards and two trapezoidal ones is clarified. To implement efficient PV generation, this paper proposes to automatically generate 3D building models for buildings topped with double shed roofs with overlaid PV arrays. The sizes and positions, slopes of roof boards and main under roof constructions are made clear by presenting a top view and side view of a double shed roof house. For the applied example of the developed system, this papers presents a simulation of the solar photovoltaic generation change of a city block by performing land readjustment and changing the shape of buildings, ordinarily roofed houses or double shed roofed houses suitable for efficient PV generation. Our simulation reveals that double shed roofed houses have greatly improved solar photovoltaic generation