Illustrator Tip #2: Aligning Irregular Shapes

Illustrator's tools are powerful, but sometimes they can't do the job without help. One of the problems I quickly discovered was aligning anything except the simplest shapes. Circles and rectangles of unit sizes were easy, but more complex shapes made up of multiple pieces were a big problem. With some effort, I found a method that works.

The Problem

Illustrator has a grid which is useful for aligning objects. If View|Snap to grid is active, control points will jump to the closest grid crossing. This is extremely handy for creating nested concentric circles and many other tasks. Yet it's not very useful when you have an object made up of two or more irregular pieces that have control points in weird places. If you have to manipulate the pieces individually, it's easy to get them misaligned. Then you have to use Undo a lot, and re-do all your work. It's no fun.

Granted, Illustrator can snap to existing control points on other shapes. Unfortunately, there are circumstances where it's not enough. For example, how can you align an object to a place where there is no point? Then you're out of luck, unless you know this technique.

Let's look at a simplified example. The following image is made of three pieces: one blue crescent, one yellow piece that completes the circle, and the outer ring lines. Together they make up a simple ringed planet.

(If you want to follow along with the sample image, you can download it. It's a 17K ZIP file in Illustrator 5.0 format.)

[Three-piece image]

Now let's blow it up, scattering the pieces randomly. Then we'll try to put it back together.

[Scattered pieces]

Let's try to move the pieces back together. It doesn't quite work, no matter how we try. The pieces don't fit together like they did originally. Even if the grid were off, they still wouldn't align exactly as they did when we started work. The arrows point to some obvious misalignments.

[Misaligned pieces]

What can we do about a situation like this?

A Solution: Handles

The key is to use the grid, but not to align the existing pieces . We'll create some new objects and use them as handles for the originals. It will be easy to align the handles, and when they're aligned, the original pieces will be aligned as well.

Re-load the original, aligned image. Turn the grid on. To one side of the window, make as many evenly spaced one-unit squares as there are pieces of your image (three, in this case). We're going to make each square correspond with a piece of the hard-to-align image. The squares act as handles to the pieces.

[image and 3 squares]

Select the first handle. Using the eyedropper, click on the first piece of the image (the yellow one). The handle now has the same outline and fill as the piece. Select the piece and the handle and group them. Repeat the process for rest of the pieces and handles. (This step isn't necessary, but comes in handy sometimes.)

[Coloring a handle]

When this is done, we'll have a set of handles that are (a) nicely aligned, and (b) have colors identical to their corresponding pieces. This helps to tell the handles apart. Yellow piece - yellow handle. Simple.

Now we can turn off the grid, move things around, and work on the pieces individually. Note that the handles move as well.

[Scattered pieces]

When you want to align the pieces again, what was previously impossible is now as simple as turning on the grid back on, then moving the handles back into alignment. In the image below, we're part way through re-alignment.

[Partly re-aligned image]

And when all the handles are back in line, the original image is perfectly re-assembled.

[Three-piece image]

Last updated 4 January 2003
All contents ©1999-2002 Mark L. Irons

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