Feature Line Extraction from Triangular Mesh Model

Feature lines such as boundaries and ridges should be preserved in transforming triangular meshes into rectangular B-spline patches.An edge-based algorithm that includes two steps ：feature point detection and feature line generation is presented.The feature points are identified by the angle bet ween the normals of adjacent triangles as well as by the principal curvatures.In the algorithm, weights and so me other measures are applied to reduce the approximation error.Feature points are linked into B-spline curve for the subsequent construction of B-rep model.