Strip away all of Illustrator's fancy features and new interface, and you're left with the heart of Illustrator--the Bézier path and the Pen tool. Since version 1.0, the Pen tool is probably the main reason why Illustrator has become one of today's best illustration programs. Comfortable, elegant, and functional, the Pen tool gives you complete control when creating and editing the base of all vector illustrations--the Bézier (pronounced BEH-zee-ay) path. In this hour, we discuss:
So what is a Bézier path anyway? It's a mathematical way of representing graphics, developed by Pierre Bézier (it was originally created to put designs of aircraft on a computer, and then later for designing cars). All vector objects are made up of Bézier path segments. Bézier paths come in two flavors, lines and curves. Let's discuss the difference between them.
The first type of Bézier path is a straight line and contains two anchor points with a straight line connecting them (see Figure 6.1). This is the simplest Bézier path and requires the least amount of memory to store and print. All that is needed is the coordinates of the first point and the second point.
The simplest of Bézier paths: A straight line.
The second type of Bézier path is the curve, and here is where it gets complicated. A curve consists of two anchor points, with a curved line connecting them. The curve is determined by control points, which are attached to each anchor point (see Figure 6.2). The control points (also called handles) define exactly how the curved line is drawn between the two anchor points.
A Bézier curve, showing the anchor points and the control points.
Of course, when the paths print, you won't see the anchor points or the handles. They are just there onscreen so that we can edit them, but when they print, all you see is the line (see Figure 6.3).
When the files actually print, you don't see the anchor or the control points.
Up until now, we've been creating Bézier paths without even knowing it. The rectangles, ellipses, stars, polygons, and spirals that we've created are all made up of Bézier paths. We were doing fine until now, so why bring in all of this complicated anchor point and control point stuff? As they say, ignorance is bliss. Sure, you could do a lot of things in Illustrator without knowing what Bézier paths are. But you lose out on all the power that Illustrator offers. There are other programs out there that have more features than Illustrator. In fact, I think it would be safe to say that of all of the major illustration packages on the market, Illustrator has the least number of features. Illustrator's power lies within the Pen tool and the implementation of Bézier paths.
CAUTION: Before we begin learning how to create and edit Bézier paths and use the Pen tool, I want to make the following disclaimer:
Drawing and editing Bézier paths requires much patience and time. But you have a lot to look forward to--it also gets better with experience. I look back now at some of the art I created as a beginner, and I can't help but wonder, "What was I thinking?" There is no doubt that you will become comfortable with the Pen tool; you just have to give it time. Do the exercises listed here, practice a lot, and before you know it, you too will be looking back in wonder. But more importantly, you will have harnessed the power of the Pen tool.
Illustrator's Pen tool is rumored to be the most inhumane torture tool ever devised by man. But fear not, there is a method to the madness, and perseverance will prevail. The Pen tool is used to create precise Bézier paths of virtually any shape or form. It works by creating anchor points, which are the basis of Bézier paths.
Just A Minute: Some of you who have used Photoshop know that there is a Pen tool in Photoshop as well, for defining clipping paths and precise selections. Both the Photoshop and the Illustrator Pen tool work identically, and you can even move Bézier paths between the two programs easily using cut and paste or drag and drop. It's integration such as this that really makes for intuitive, useful, and practical applications.
There are three different kinds of anchor points: the straight corner point, the smooth point, and the combination point. Each kind of anchor point has its specific attributes, and each is used to create different types of paths. A Bézier object can be made up of any of the three kinds of anchor points and can contain any combination as well. A square is made up of four straight corner anchor points, for example, whereas a circle is made up of four smooth anchor points. A shape such as a pie wedge contains both straight corner and smooth anchor points. As we go through the following hands-on exercises, you'll get a better feel for anchor points and understand how they work.
Time Saver: Throughout this chapter, and the rest of the book, we will be doing different exercises in Illustrator. Although you can use this book without them, the files that I have used for Illustrations are available on the World Wide Web if you want to follow along. Simply direct your browser to http://www.mordy.com.
The straight corner is the simplest form of the anchor point, and it is used to define straight lines such as the ones shown previously in Figure 6.1. Before we begin using the Pen tool, it should be mentioned again that Illustrator's cursors change to indicate the current status of a tool. The subtle differences in the Pen tool cursor will be pointed out as they occur. If you goof anytime throughout the exercises, don't worry, just use the Undo command (Command-Z)[Control-Z].
2. Select the Pen tool from the Toolbox (see Figure 6.4). Notice that the Pen tool cursor has a small "x" on the lower right (see Figure 6.5). This indicates you are starting a new path.
Selecting Illustrator's Pen tool.
The tell-tale cursor. The little "x" indicates the Pen tool is ready to create a new path.
Two segments of the triangle, completed.
By showing the little "o", the Pen tool is indicating that clicking will complete and close the path.
After completing the triangle, the Pen tool is ready for its next assignment.
Congratulations! You have just created your first shape with the Pen tool. Don't jump for joy just yet, the hard part comes next: The smooth anchor point.
The smooth anchor point contains two control points, or handles. By adjusting the control points, you determine the slope and sharpness of the curve on either side of the point. Because the path continues through the point without a sharp change in direction, it is called a smooth anchor point.
When you press the mouse button, you define where the anchor point is. By dragging, you define where the control point is.
3. Move your cursor about one inch down and to the right of the first anchor point--not the control point (see Figure 6.10).
Without clicking, you move your cursor to where the next anchor point will be.
While still holding down the mouse button, drag as shown.
6. Move your cursor one inch down and to the left of the last anchor point you created (see Figure 6.12).
Repositioning the cursor for the next step.
8. Release the mouse button. We're halfway there!
9. Move your cursor one inch up and to the left of the anchor point you just created (see Figure 6.14).
Dragging out another control point.
This is the last anchor point, bringing the total anchor points in this shape to four.
Dragging out another control point.
12. To complete the circle, repeat Step 1--click the first anchor point we created and drag about half an inch to the right (see Figure 6.16).
Completing the circle.
So we see that by pressing and dragging a point, we can create a smooth anchor point with control handles. Control handles determine the direction of the curved path. To demonstrate, switch to the Direct Selection tool (the white arrow) and click the line of the circle. The control points are now visible for that section of the path. Press and drag on one of the control handles, and see how the path behaves when you move the control point.
Generally, the direction of the curve follows the control point. Try to avoid stretching the handles too far from the anchor point as it makes for difficult editing (the ideal guideline shouldn't exceed one third the length of the curve). Again, as you work more and more with control points, you get a better idea of where to place them and how to achieve the curve you want.
Okay, we're building confidence now, and we're really going to need it. The Combination Point is--get this--a combination of the straight anchor point and the smooth anchor point, and things can get a bit confusing.
2. Position your cursor one inch to the right of the first anchor point.
Dragging the first point.
A single click completes the path--the first anchor point was a smooth point, the second a straight point.
Notice the change in the Pen tool cursor.
6. Repeat Steps 2 through 5 (see Figure 6.20).
Making waves.
In the above exercise, you create a straight anchor point, which has no control handles, when you click. By dragging out of the straight point, you are defining the next connecting path and anchor point. So, in reality, the combination point has two sides to it: a straight side (from the single click) and a curved side (from the click and drag).
True, in these examples, you were told where to place the anchor points and the control points. If you were creating any other random shape, you would have to decide where those points belong on your own. After getting a feel for how anchor points and control points affect the path, you will be able to make these decisions on your own. I've included several other templates, shown here, that you can use to get a better feel for the Pen tool.
A path in Illustrator can either be open or closed. An open path has two endpoints, whereas a closed path has none--one end joins the other. As you draw with the Pen tool, Illustrator uses the current fill and stroke attributes for your shape. As you complete each click, Illustrator attempts to fill the shape using the current fill, so do not be alarmed. Just continue following the steps in the exercise. We cover fills and strokes in detail in Hours 10 and 11.
Whew! This was the hardest chapter yet. Give yourself a big hand for making it through the horrors of the Pen tool. But don't worry, it will become second nature before you know it. We also learned about Bézier paths and the different kinds of anchor points. Next we work with Bézier paths after we've created them. This is going to be fun!
Bézier path--A mathematically defined line consisting of anchor points and control points.
Open path--A Bézier path with two open (unconnected) endpoints.
Closed path--A Bézier path that is fully enclosed; it has no beginning and no end.
Anchor point--A defined point on a Bézier path.
Control point--A defined point that is part of an anchor point, used to control the curve of a path.
Smooth point--An anchor point in which its control points are tangent to the anchor point.
Corner point--An anchor point with no control points; for defining straight lines.
Combination point--An anchor point that shares the attributes of both a smooth point and a corner point.
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