Draw a curve in the blue panel and it will reappear in the white panel with a bezier curve added. You can remove the line segments to see only the curve in the white panel by pressing polygon once and again to bring it back. Use the faster and slower buttons to speed up input: faster = more points, slower = fewer points. Try it out. This models should handle any numberr of points but remember that every point on the bezier curve itself is dependent on EVERY point on the drawing no matter how far away. Start with small, short, simple curves to realize what it is doing.