Research on Algorithm for Contour Lines Offset and Interference Elimination

Some problems about the offset of contour lines which consist of sequential lines and direction complies with left hand rule are studied. Point-normal equation and parametric equation of offset lines are used to compute the vertex of offset contour lines. To eliminate the interference,the offset contour lines are changed into isolated contour lines without intersections,and then the interferential contour lines are removed based on the cross product of two vectors on the intersections.