Illustrate the methods of editing a curve by manipulating its control points, edit points, knots, and degree of polynomial.

What will be an ideal response?

Understanding that the degree of polynomial has a direct influence on the number of control points, you will now learn how to manipulate control points to modify a curve. You can change the location and the weight of the control points. You can also delete control points to simplify the shape of the curve. Because control points are normally not lying along the curve, you may find it difficult to make a curve pass through designated locations by manipulating the control point. To add flexibility in modifying a NURBS curve, Rhino enables you to use edit points along the curve. Edit points are independent of degree, control points, and knots of a curve. One of the ways to modify a curve is to raise or reduce its polynomial degree. Simply raising the degree of a polynomial spline curve does not change the curve’s shape, but it does increase the number of control points. In turn, more control points enable you to modify the curve to create a more complex shape. On the other hand, reducing the degree decreases the number of control points and hence simplifies the shape of the curve.