Abstract: The algorithm presented in this paper firstly obtains the data matrix of the clear outline of planar complex patterns through vectorization and data conversion of the planar complex pattern image or graphic,secondly finds the intersection points of scan lines and contours using scan analysis method,and matches the intersection points and calculates midpoints,finally builds the 3D model of the planar complex patterns by the 3D model data matrix that is created using quadratic Bezier curves and post-optimization processing of the model data．This modeling approach can conceive and build a virtual model of the plane patterns．It can generate smooth and delicate curving surface and vivid model which has the basic structure characteristics of the patterns,and flexibly control the model generating form．The mode-ling algorithm has the features of low complexity,fast modeling speed,and strong practicality．

Key words: Complex pattern,Scanning analysis,Quadratic bezier curve,3D modeling