Research On 3D Reconstruction Method For Typical Ship Structure

The engineering drawing, made up of the three views, have been a general method expressing the 3D solid completely with 2D information in engineering project. Modeling 3D solid is intricacy, so it is necessary that a conversion is set up from engineering drawings to 3D solid model.A 3D solid is made up of a series of 3D features, so the key task is how to recognize the 3D feature information from 2D drawing data.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 format, 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 on STEP standard and feature tree and by adopting manual and automatic ways, the feature assembly relation is determined.Based on AutoCAD, the structure of the 3D reconstruction system, the interface and implementing ways are put forward.