Complex curved surface creation method

Claim 1

A complex curved surface creation method for creating a complex curved surface composed of at least two three-dimensional curved surfaces, comprising the following steps: (a) inputting data for specifying each of said three-dimensional curved surfaces, and inputting data specifying a single specified line of intersection on a reference plane and inputting a rule for determining additional lines of intersection of section planes with said reference plane on the basis of said single specified line of intersection; (b) finding a plurality of section curves of the complex curved surface, each of said section curves lying in an i-th section plane having an i-th line of intersection, among said additional lines of intersection, with said reference plane, including the steps of: (bi) dividing each of said three-dimensional curved surfaces into a plurality of patches each comprising a quadrilateral by using the inputted data; (bii) obtaining coordinates of points of intersection between an i-th line of intersection and the sides of the patches projected onto said reference plane; (biii) obtaining coordinates of points, each point lying on one of the three-dimensional curved surfaces and corresponding to one of the points of intersection; and (biv) obtaining section curves by assembling said points on the three-dimensional curved surfaces; and (c) machining a complex curved surface using an assemblage of the section curves lying in said section planes forming respective ones of the single specified and additional lines of intersection with said reference plane.