Abstract: An approximation processing method for approximating a point group using a curve or a surface defined by control points includes a step of forming an approximated curve (surface) using control points that retain features of a shape; a first calculation step of calculating a closest point closest to each of the data points on the approximated curve (surface); a second calculation step of calculating an error vector that joins the closest point, obtained in the first calculation step, to the data point; and a third calculation step of calculating a corrected control point by moving each of the control points based on the error vector obtained by the second calculation step. The step of forming an approximated curve (surface) and the first to third calculation steps are repeated to make the approximated curve (surface) respectively approximate the curve (surface) of an object configured by the data points.

Abstract: An approximation processing method for approximating a point group using a curve or a surface defined by control points includes a step of forming an approximated curve (surface) using control points that retain features of a shape; a first calculation step of calculating a closest point closest to each of the data points on the approximated curve (surface); a second calculation step of calculating an error vector that joins the closest point, obtained in the first calculation step, to the data point; and a third calculation step of calculating a corrected control point by moving each of the control points based on the error vector obtained by the second calculation step. The step of forming an approximated curve (surface) and the first to third calculation steps are repeated to make the approximated curve (surface) respectively approximate the curve (surface) of an object configured by the data points.

Abstract: A shape evaluation device performs simulation by using an annular light source or concentric light source instead of a rectilinear light source and calculates a characteristic line for performing shape evaluation. The shape evaluation device includes a calculation device (2) having: a distance vector calculation unit (2a) for acquiring a distance vector representing a distance between the circle and the vector, a distance function unit (2b) for acquiring a distance function from the distance vector, and a distance function calculation unit (2c) for acquiring a point on a curved surface where the value of the distance function is a predetermined value. By performing simulation using the annular or concentric light source, it is possible to obtain a characteristic line capable of observing distortion in all the directions by one calculation.

Abstract: A shape evaluation device performs simulation by using an annular light source or concentric light source instead of a rectilinear light source and calculates a characteristic line for performing shape evaluation. The shape evaluation device includes a calculation device (2) having: a distance vector calculation unit (2a) for acquiring a distance vector representing a distance between the circle and the vector, a distance function unit (2b) for acquiring a distance function from the distance vector, and a distance function calculation unit (2c) for acquiring a point on a curved surface where the value of the distance function is a predetermined value. By performing simulation using the annular or concentric light source, it is possible to obtain a characteristic line capable of observing distortion in all the directions by one calculation.