3-d Building Reconstruction from Unstructured Distinct Points

This paper presents a model-based approach for 3-D building reconstruction unstructured distinct points. The data structure of a building is an unstructured roof point cloud digitized by operators. Constructive Solid Geometry (CSG) model is applied in our approach for a complex roof which can be decomposed into three types of primitive models. The primitive model is represented as a tree. The leaves contain primitives and the nodes store Boolean set operators to combine primitives to form a whole building. There are three steps in this approach. The key process during the entire reconstructing procedures is rectangulation, which is to form points automatically into horizontal rectangular bases of primitive roof models. In the second step, we determine the primitive roof model by its rectangular bases and the corresponding roof points. A primitive roof or a combination of roof primitives can then be assembled to a polyhedral roof model in the third step. The building can be completely reconstructed by projecting its roof boundary outline to ground. Because of the rectangulation process, our method has limitation in only describing the buildings with right angle corners. Nevertheless, under this assumption, the result shows that our methodology can successfully reconstruct buildings with complex roofs over Purdue University campus. We demonstrate the results with pertinent discussions.