Edit B-Spline control points
Editing the position of control points in B-Spline shapes is similar to editing Bezier shapes. In fact, the steps for selecting, moving, adding, deleting, and locking control points are almost exactly the same. The main difference in editing both types of shapes lies in how you manipulate and adjust curves.
The simplest, and usually fastest, way to manipulate B-Spline curves is to move B-Spline points closer to or farther from one another. When B-Spline points are moved closer to one another, a sharper curve is created. B-Spline points that are farther from one another create shallower curves.
Each B-Spline control point tugs on a section of the shape, pulling it toward itself. As a result, you manipulate a shape’s curve by moving its control points in the direction you want to pull the shape. For example, notice how every control point creating the S curve below is offset in the direction of the curve it influences.
Note: You can show and hide the B-Spline frame lines that enclose B-Spline control points by choosing View > Overlays > Lines.
By default, B-Spline shapes have no corners. However, you can adjust the amount of curvature at each B-Spline control point to create sharper curves using fewer control points. (You can even create corners at a single point, if necessary.)
The easiest way to adjust B-Spline point curvature is by dragging the control point while holding down the Command key. You can also switch among three preset degrees of curvature.
Adjust B-Spline control point curvature
Select a shape, then click and hold the 2D transform tools pop-up menu and choose the Edit Points tool.
In the Canvas, drag selected B-Spline control points while holding down the Command key to make their curves progressively sharper.
A handle appears indicating the curvature adjustment you’re making.
Do any of the following:
Drag away from the point to make the curve progressively sharper.
Drag toward the point to make the curve progressively looser.
Note: After the handle appears, you can modify the curve without the Command key.
Command-click the handle to switch between three progressively sharper amounts of curvature.
Alternatively, you can Control-click a B-Spline point, then choose Very Smooth, Smooth, or Linear from the shortcut menu.