Adobe Illustrator CS5 : Organizing Your Drawing - Enhancing Appearances with Live Effects

Illustrator refers to effects as live effects. There are several reasons for this. First—and most important—any effect you apply from the Effect menu is added as an attribute in the Appearance panel. Second, all effects can be edited at any time, even after the file has been closed and reopened at another date. Finally, when an object’s path is edited, any effects that are applied to that object are updated as well. Because these effects are nondestructive, they are considered “live” and are always editable.

The way that Illustrator accomplishes this behavior is by keeping the underlying vector object intact, while changing just the appearance of the object by adding the effect. Think of those 3D glasses you used to get at the movie theater. Without the glasses, the movie is nothing special, but once you don the glasses, the movie appears to be 3D. You can think of the Appearance panel as a pair of 3D glasses in this sense—once you add an effect, the object changes in appearance, but the original untouched vector paths remain beneath the hood (Figure 1).

You can choose from many live effects in Illustrator, including those that are vector-based (such as Scribble) and those that are raster-based (such as Gaussian Blur).

Applying a Live Effect

You can apply a live effect, such as a drop shadow, to a target in two ways: choose Effect > Stylize > Drop Shadow or click the Add New Effect button at the bottom of the Appearance panel and choose Stylize > Drop Shadow (Figure 2, on the next page). The Drop Shadow dialog box appears, where you can specify the exact settings for the drop shadow including the blending mode, opacity, offset (the distance between the object and its shadow), and blur amount (the softness of the shadow). Additionally, you can choose a color or darkness value for your drop shadow (Figure 3, also on the next page). Note that the dialog box has a Preview option, which, when selected, lets you see your shadow update as you make changes to the settings. Once you’re happy with the appearance of your drop shadow, click OK to apply it.

Now, let’s take a look at the Appearance panel. Note that the path is listed as the target, and then examine the attributes in the object itself. Reading from the bottom up (the order in which the attributes are drawn), you have the default opacity, the Drop Shadow effect you’ve just applied, the fill, and finally the stroke of the object (Figure 4). The drop shadow appears beneath the fill and the stroke of the object because it wouldn’t be much of a drop shadow if it were painted above the fill and stroke, would it?

The truth is, you can use the Appearance panel to control exactly how and where your drop shadow—or any live effect—is painted. You can target the Fill or Stroke attribute in the Appearance panel and then add the drop shadow. In this way, you can add a live effect to just the fill or just the stroke of an object. If your object contains multiple fills or strokes, you can apply live effects to each of them individually (Figure 5). Even though you’ve already applied a live effect to an object, you can drag the effect within the Appearance panel to change its place in the stacking order or to apply it to a specific fill or stroke (Figure 6, on the next page).

Editing a Live Effect

One of the important benefits of live effects is that you can edit them at any time. Clicking the blue underlined name of an effect that is listed in the Appearance panel opens the dialog box for that effect, where you can view the current settings and change them at will (Figure 7). This may be confusing initially, because you’d think that in order to change an effect, you’d return to where you first applied the effect (that is, the Effect menu). Doing so actually adds a second effect to the selected object (Figure 8). Illustrator allows you to apply an effect to an object as many times as you’d like, you will explore when that might be beneficial. The important thing to remember is that when you want to add a new effect to an object, you do so by using the Effect menu or by clicking the Add New Effect button. To edit an effect that already exists, click its name in the Appearance panel.

Loading Attributes with the Eyedropper Tool

You can use the Eyedropper tool in Illustrator to load the attributes of existing objects quickly. This can be useful in two ways. First, if you already have an object selected when you click another object with the Eyedropper tool, your selected object changes to match the object you clicked. Second, you can click once with the Eyedropper tool to sample the attributes of an object, and you can then Option-click (Alt-click) to apply those attributes to other objects in your file without actually having to select them.

You can configure the Eyedropper tool to sample just the basic appearance of an object (the topmost fill and stroke) or complete complex appearances. To control what the Eyedropper tool can sample, double-click the tool in the Tools panel.

Shift-click with the Eyedropper tool to sample colors from the pixels of raster images (or even the visual appearance of vector objects). In this way, the Eyedropper tool works much like the one in Photoshop.