2012

To switch between displaying control vertices and displaying fit points, click
the triangular grip.
IMPORTANT Switching from displaying control vertices to fit points automatically
changes the selected spline to degree 3. Splines originally created using
higher-degree equations will likely change shape as a result.
In general, editing a spline with control vertices provides finer control over
reshaping a small section of the curve than editing a spline with fit points.
You can insert additional control vertices to a section of a spline to obtain
greater control in that section at the expense of making the shape of the spline
more complicated. The Refine option adds a knot to the spline resulting in
replacing the selected control vertex with two control vertices.
854 | Chapter 19 Select and Modify Objects