C H A P T E R 1 1

Icons

Icon Perspectives and Materials

The angles and shadows used for depicting various kinds of icons are intended to reflect how the objects would appear in reality. All Aqua interface elements have a common light source from directly above, not from the upper-left corner as in Mac OS 9 and earlier. The various perspectives are achieved by changing the position of the camera capturing the icon.

Application icons look like they are sitting on a desk in front of you.

Figure 11-20 Perspective for application icons: Sitting on a desk in front of you

Utility icons are depicted as if they are on a shelf in front of you. Flat objects appear as if there is a wall behind them with an appropriate shadow behind the object.

Apple Computer, Inc. June 2002

C H A P T E R 1 1

Icons

Figure 11-21 Perspective for flat utility icons: On a shelf in front of you, with a shadow on the wall behind

An actual three-dimensional object such as a rocket, however, would more realistically be viewed sitting on the ground; its icon shows the rocket sitting on a shelf, with its shadow below it.

Figure 11-22 Perspective for three-dimensional object: Sitting on a shelf in front of you, with the shadow below the object

For toolbar icons, the perspective is also straight-on, as if the object is on a shelf in front of you.

214Icon Perspectives and Materials

Apple Computer, Inc. June 2002

C H A P T E R 1 1

Icons

Figure 11-23 Perspective for toolbar icons: Straight-on, with subtle shadow on the “floor”

Icons that represent actual objects should look as though they are made of real materials. Examine various objects to study the characteristics of plastic, glass, paper, and metal. Your icon will look more realistic if you successfully convey the item’s weight and feel, as well as its appearance.

Use transparency only when it is convincing and when it helps complete the story the icon is telling. You would never see a transparent sneaker, for example, so don’t use one in your icon.

Figure 11-24 Materials: Transparency used to convey meaning

Apple Computer, Inc. June 2002

C H A P T E R 1 1

Icons

Conveying an Emotional Quality in Icons

Figure 11-25 illustrates the difference between communicating a message in a straightforward way compared with presenting the same message with an emotive quality. In an appropriate context, we would recognize the figure on the left as the symbol for men’s bathroom. The figure on the right, however, tells a story even when it is viewed outside of its context.

Figure 11-25 Being emotive: The same message conveyed two ways

Suggested Process for Creating Aqua Icons

You need to provide at least the following files:

■a 128 by 128 image (for Finder icons)

■a mask that defines the image’s edges, so the operating system can determine which regions are clickable

216Conveying an Emotional Quality in Icons

Apple Computer, Inc. June 2002

C H A P T E R 1 1

Icons

Icons that display in the Finder are viewed at different sizes: they can be magnified in the Dock, they can be previewed at full size, and users can specify a preferred size. For the best-looking icons at all sizes, you should also provide customized image files (“hints”) at three other sizes: 64 x 64, 32 x 32, and 16 x 16. Although the Dock doesn’t use hints (it uses a sophisticated algorithm on the 128 x 128 version), hints are important for preserving crucial details in Finder icons.

If you are creating an icon that will never change size—on a bevel button, for example—you can supply the image only at actual size.

Here are the suggested steps for creating an icon:

1.Sketch the icon.

Work out the concept and details of your design on paper, not with software. You should be ready to execute the idea by the time you open an application.

2.Create a software illustration of the icon.

Although you may want the final icon to look like a photograph, in most cases it’s inadvisable to start with an actual photograph. An illustration provides much more flexibility for conveying a concept in a very small space. An illustration also gives you necessary control over details, perspective, light and shadow, texture, and so on.

3.Add detail and color.

For each enhancement you make to a larger-version icon, consider whether it is truly adding something to the icon’s usability, or whether it is just adding complexity or clutter.

4.Add shadows.

Shadows give objects dimensionality and realism. They also help tie the elements of an icon together so it doesn’t look like a collage. The light source should be above and slightly in front of the object. The resulting shadow should create the sense that the icon is resting on a surface.

5.In an image-editing program, manipulate the image to get precise effects and create the icon mask.

6.Convert the icon to a .icns file.

You can complete this step with Icon Composer, included on the Mac OS X Developer Tools CD. There are also several third-party tools available for completing this step.

Apple Computer, Inc. June 2002