Adobe Illustrator CS5 One-on-One

Drawing Fluid Bézier Curves

So far we’ve seen how to draw corner points with the pen tool, and

even soften those corner points using spline curves via Illustra-

tor’s round corners effect. But the true power of the pen tool, and

of curves, can be realized only by using Bézier curves and the two

new types of points it introduces: the smooth point and the cusp

point. (For a full explanation of the different types of points, see

the sidebar “The Three Kinds of Anchor Points” on page 98.)

Bézier curves are calculated differently than spline curves. Rather

than connecting to the center of each segment and curving to avoid

the corner points as spline curves do, Bézier curves run through

each point, and the control handles determine how the path bends,

as illustrated in Figure 3-24. (The path is shown in light blue, the

points in dark blue, and the control handles in green.) With a Bézier

curve, the path always bends toward the control handle, almost

gravitationally. Also unlike spline curves, Bézier curves affect the

path itself, rather than simply how the path is rendered.

In this exercise, we’ll trace the head of the fearsome underwater

panther, the fabled mishipizheu, taking full advantage of the Bézier

curves that the pen tool makes available.

Figure 3-24 .

Figure 3-25 .

path

control handle

point

1.

Open the artwork. If you have your fi le from

the preceding exercise, open it now. Other-

wise, you can open an in-progress document

called Mishi canoe.ai, found in the Lesson 03 subfolder

inside the Lesson Files-AIcs5 1on1 folder. You should

see the now-familiar tracing template as well as a com-

pleted canoe.

2.

Add your fi rst point. First, confi rm that your fi ll is set

to None. Zoom in close to the mishipizheu’s head, as

shown in Figure 3-25. Press the P key to make the pen

tool active. Instead of clicking to add a point (which

would add a corner point), I want you to drag from the

pen pointer to the end of the arrow seen in Figure 3-25,

releasing the mouse button when you roughly reach the

spot marked by the arrowhead. This creates a smooth

point, complete with control handles.

The farther you drag from the start, the longer the control

handle. A longer control handle exerts more “pull” on the

path, pulling it farther from a straight segment. While you

won’t see any difference on this fi rst point, as you add more

points to your path the effect will become clear.

96

Lesson 3: Using the Pen Tool