3D Modeling Of A Ship Based On Profile Diagram

In order to improve the calculation accuracy of the mathematical model for ship's floating state,stability,strength,as well as reducing the workload of artificial modeling.In this paper,based on the ship profile,use NURBS(Non-Uniform Rational B-Spline)surface interpolation to reconstruct the three-dimensional design model of ship hull.The main work is as follows:(1)Analysing the structure of ship's CAD engineering drawings(DWG&DXF),loading to obtain ship's shape data;(2)Calculate the control points corresponding to the points of each lateral,and interpolate NURBS curves to obtain encrypted laterals,which is used as a new basic data.This enables NURBS surface interpolation to obtain any desired denser control lattices when calculating control lattices.(3)On the basis of the encrypted waterline data,the encrypted data are parameterized along the longitudinal and vertical directions of the ship respectively.The NURBS surface interpolation is used to calculate the control point matrix of the hull surface,and the hull surface is inversely calculated according to the control point matrix and parameter vector obtained,and the three-dimensional model file is generated.This method divides ship form data according to lateral,realizes the reconstruction of complex hull with single surface using NURBS surface interpolation,avoids the problem of splicing gap and smoothness caused by splitting complex surface reconstruction into multiple surface patches.Taking the bulk carrier "JZSY-47500-8" designed by Shanghai Ship Design Institute as an example,the three-dimensional model of the ship is reconstructed,and the Hydrostatic Calculation of the ship is carried out.The model is in good agreement with the original ship three-dimensional design model in shape.Comparing the calculated results with the loading manual values,the absolute maximum relative error of hydrostatic parameters is less than 0.65%.It is proved that the method can be used to reconstruct the ship's three-dimensional model as the data source of the three-dimensional model of the stowage instrument.At the same time,the reconstruction method is helpful to improve the accuracy of ship three-dimensional modeling in marine simulator and reduce the workload of artificial modeling.