3D Building Modeling Based On DXF Data

Three-dimensional virtual models of buildings are widely applied in many areas, such as housing show, scene simulation and game entertainment. Artificial constructing three-dimensional model requires professional software and requires highly qualified developers, with heavy workload and low-level automation. At present,3D reconstruction which generates three-dimensional shape from two-dimensional planar data is in a higher automation degree. For building modeling, the3D reconstruction method based on architecture plan has unique advantage.Usually, there are three main steps in3D reconstruction of architecture plan. Firstly, the reconstruction needs obtaining geometric data from plans, including point, line, arc and circle etc. Secondly, it identifies building components, what means that recognizing wall, door and window from geometric data according to their graphic feature. Thirdly, it assembles these building components into a whole3D model of building after producing them.By analyzing the regular of architectural drawing and the feature of DXF file, this paper implements a3d reconstruction system which automatically generates building model from DXF data of architecture plan. Corresponding to three steps above, the system composed of three modules as follows:1. Reading module for plan. The module analyzers the feature of DXF files with drawing knowledge, and obtains planar data, such as layer, line, arc and block and so on.2. Parsing module for planar data. The module identifiers building component, including wall, door and window, from planar data, then converts them into closed contour, getting complete planar information.3. Exporting module for3D data. The module stretches2D plane, generating3D model of building, then saves3D data as VRML file and OSG file. The VRML files and OSG files exported by the system have been used in virtual walkthrough and crowd simulation. The result of testing show that the system accelerates the speed of modeling, and the exported models are precise enough for a variety of applies.