Simplification of 3D City Model with CityGML

Abstract

Many applications demand simplified 3D building models for fast visualization and analysis purposes. However, due to the huge spatial data, it intensifies the load of the computer in the visualization process, and the redundancy of the data also affects the user experience. So in order to solve the above problems, this paper presents a method of 3D city model simplification, it can preserve the location and the overall model shape using the semantic filtering and edge search combining to simplify the model, reduce data redundancy, extracting model of shell. The proposed method mainly uses the semantic filtering to extract the wall and roof structure, and remove the doors and windows, then through the proposed adjacent search algorithm to extract the model to simplify the removal of the thickness of the wall and roof, leaving only the outermost model. The approach has been implemented and tested on a number of 3D buildings. Experiments show that the simplified model, when there is no significant difference in the visualization of the case, by calculating, the simplified model is compared with the original model, reducing the number of about ninety-seven percent, the size of the model is reduced to about two percent of the original.