BVIFM: A Vector Model for Calculating Sunlight Shadow Effect of Terrain on Neighboring Buildings

摘要

In order to solve the current problem of the sunlight analyzing models, which are not suitable for most of the mountainous and hilly areas because of ignoring the factors that the topography influences the sunlight, this article will integrate the principles and ideas of "Shadow Equivalence", "Reverse Sunlight" and "Sky Graph", and will propose "Backlighting Vector Intersecting Shadow Projection SurFace Model" (BVIFM), from the angle of the Geometrical Optics. Besides, this article will use a certain residential district in Chongqing Province and the actual terrain data (DEM) as examples to verify the validity and correctness of the BVIFM. The results from the experiments show that the BVIFM can be quite satisfactory, while calculating the sunlight effects caused by the uncertain mountains and hills on their neighboring constructions. The proposal of the BVIFM can not only remedy the shortcomings of the current models, but also provides a new solution for the sunlight calculation as well as laying a foundation of a unified model of the sunlight analysis.