Reading, Recognition And 3D Reconstruction Of AutoCAD Architectural Drawings

With the development of computer technology, computer-aided design tools like AutoCAD have been used by many architectural designers. However, most 3D architectural structural information is still expressed by 2D drawings. It is difficult to reconstruct 3D architectural model from 2D architectural drawings automatically. Hence, technologies of computer graphics and image analysis and processing are always used to read and recognize architecture objects.In recent years, the demand of using AutoCAD architectural drawings to automatically build three-dimensional architectural model is growing rapidly. Recognition, understanding and three-dimensional reconstruction of 2D architectural drawings is a cross research field which includes computer graphics, computer-aided design etc. Related research topic has become a focus.In order to solve this problem, some researches on reading, identification and 3D reconstruction of building were done.First of all, by analyzing the structure of DXF file, a cross-platform, open source library DXFLib was adopted to read DXF information, and do some pre-processing operations.Then, by analyzing the content, features and drawing style of the floor plan, knowledge based understanding strategy and geometric constraints recognition methods were proposed based on the principle of professionals'3D building modeling.Furthermore, this paper proposes an algorithm to identify walls from floor plans. Wall is the most important part in the architectural structure, and wall recognition is the most important step in the floor plan recognition processes. After recognizing walls, other architectural component like doors and windows can be recognized more easily under the constraints with the walls.Finally, using the three-dimensional building information obtained above, the implementation of displaying 3D building model was discussed taking advantage of OpenGL.Through above works, reading, identification and reconstruction 3D model from DXF files were implemented. All these have been applied in actual project of indoor wireless networks design, reaching a relatively satisfying result.