Research And Development Of 3D Model Reconstruction System Based On ObjectARX

As a kind of formal, common language in traditional engineering, three two-dimensional orthographic views play an important role in expressing designers' intention, drawing up working procedure and exchanging. For a long time, the drawings have being recognized manually. This doesn't keep up with the development of new CAD/CAM technology. The reconstruction of 3D model from three 2D orthographic views automatically has been an important research direction in both the technology of CAD/CAM and C&G fields. Although a lot of valuable theories and technology have appeared since the subject was first brought forward by Idesawa in 1970, the real application remains to be an unresolved problem, which needs further research.After discussing the usual presentation of 3D model and contrastively researching the past many primary algorithms, such as wireframe-oriented approach and model-oriented approach, this paper decides to use the model-oriented approach which bases on CSG to realize the reconstruction. In this paper, the advanced transaction is carried out firstly, and during the view separation, an approach called moving-line is used. Thinking about the real practice, this paper divides the reconstruction process into four parts: information identification, character match, elementary solid creation and elementary solid combination, and according to each parts' point, the detailed process of reconstruction is discussed.Using the CSG model, the paper researches the arithmetic of graphics information identification on the platform of AutoCAD with ObjeetARX. In the process of reconstruction, the technology of Extension Data (Xdata) is used to memory the identified information; the approach and flow of information match are designed; the judgement of false or true character of solids is perfected.In order to validate the approach and the new project of 3D reconstruction, using the function of ObjectARX, a software system based on AutoCAD is developed with VC++ which is an advanced programming tool, and certain elementary tests by some samples have been carried out. The results indicate that the arithmetic is feasible for the elementary solids and their combination.