Research On 3D Object Reconstruction System Based On AutoCAD

"The 3D Object Reconstruction" has been one of challenging problems in the computer graphics field for almost thirty years. It is one of the important means of solid model construction. Constructing 3D model from 2D engineering drawings that express 3D object in fact, becomes on important aspect of intelligent understanding.From the practical view, this paper summarizes the theory of orthogonal projection based on the first-angle projection, the ways of manual reading drawings and discusses the problems relevant. The mechanism similar with CSG is used to reconstruct 3D object with priority to CSG and aid by B-rep. Systematically understanding shape from two perspectives of the feature and boundary model has the same advantage as algorithm of both model inducting and understanding from the bottom to top. Based on the above work, a 3D reconstruction method from the engineering drawings is put forward.For reconstruction from 2D drawings to 3D model, a method to unify 2D data-file formate, to divide views and to set up view's connection and coordinate system is proposed. The data structure is designed to express the feature's information and the algorithm of feature recognition is studied. The standard library is built, and manual and automatic'recognition are combined for feature recognition. Based onSTEP'standard and feature tree and by adopting manual and autmatic'ways, the feature'assembly relation is determined.Based on AutoCAD, the structure of the 3D object reconstruction system, the interface and implementing ways are put forward. Applying ObjectARX, a development tool AutoCAD supply, the basic function of system is realized in the surroundings Visual C++.