Patent ID: 8350853

Claim:
An interpolation processing method for interpolating a point group using a curve or a curved surface represented by control points wherein said point group has position information on each of interpolation points and vector information on a unit direction vector that defines a direction and a curvature of a curve or a curved surface at the interpolation point, said interpolation processing comprises: a first interpolation step of performing a geometry algorithm operation for finding a first point on the curve or the curved surface defined by control points based on the position information on each interpolation point, said first point being a foot of a perpendicular line dropped from the interpolation point onto the curve or the curved surface; a second interpolation step of performing a geometry algorithm operation for finding a second point based on the vector information, said second point being a point of contact between a tangent of the curve and the curve or between a tangent plane of the curved surface and the curved surface, said tangent or said tangent plane being perpendicular to the unit direction vector; and a third interpolation step of performing a geometry algorithm operation for finding a vector going from the first point to the interpolation point, a vector going from the second point to the interpolation point, and a vector going from the second point to the first point as moving vectors and for moving a position of a control point, which defines the curve or the curved surface, using one moving vector, selected from said moving vectors, for determining a moved position as a position of the control point of a new curve or a new curved surface, and operation processing for performing the interpolation steps is carried out iteratively by operation means in which the geometry algorithms are included, wherein the operation means includes a processor.