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IntroductionThis article describes how to approximate superellipses (Lamé curves) in CorelDRAW. The approximations presented are not mathematically rigorous (there are other options if you need that), but they are simple, and look good.Approximating SuperellipsesSuperellipses can be approximated in CorelDRAW using the B-Spline Tool (introduced in CorelDRAW X5). The basic idea is that if the b-spline's control polyline (the line connecting the b-spline's control points) is an octagon with alternating side lengths, the resulting b-spline will approximate a superellipse.The easiest way to accomplish this is to snap the control points to a grid:The picture above shows a 6x6 grid (I used a graph paper object as a temporary guide, although the normal grid would work). The control points (blue dots) are placed on the verticies of an octagon (shown in blue). The resulting b-spline, shaded in green, approximates a superellipse.The roundness of the superellipse can be controlled by varying the lengths of the control octagon's sides:Another WayHere is an alternate pattern of control points that approximates a superellipse. It is convenient because it can be created on a simple rectangle. Just snap the control points to the verticies (nodes) and midpoints of the rectangle's edges.Superellipses with n < 2The above approach works well for superellipses with n > 2. To approximate superellipses with 0 < n < 1 (e.g., astroids), create a 4-point star with the Star Tool, and place the b-spline's control points on its vertices. The shape ("sharpness") of the star dictates the shape of the resultant b-spline:In this case, the outer vertices must be clamped (hold v while creating, or select them with the Shape Tool and clamp them in the property bar).The case where 1 < n < 2 is harder to approximate simply. You must add extra control points to slightly "puff out" the sides. Here is an example created on a 17x17 grid::