Sunlight and shadow impact
We have developed a generic method that allows sunlight and shadow computation on huge 3D city models for impact analyses of each city object (terrain, buildings, trees, etc.) on its surroundings (close and far). This means that besides checking if a city object is shaded or not, we know which objects are responsible for the shade, thus allowing various impact analyses on cities. It could be used, for example, to compare the impact of different competing scenarios and help the decision-makers to choose one project. This method can process large city models thanks to a tiling process and the definition of a semantic Bounding Volume Hierarchy. It supports city models with different types of city objects and relies on the utilization of the CityGML standard.
We compute sunlight and shadow information for objects of different types (buildings, terrain, trees, etc.). We store the sunlight information and the shadow impact of each city object for a given date and time.