Illustrator Tip #3: Aligning Rotated Objects

Illustrator isn't designed for working with shapes that have rotational symmetry. With a little ingenuity, though, it's possible to make perfectly aligned objects with rotational symmetry.

The trick is to start well. If you want to make something with rotational symmetry, your first step should be to make a small circle. Turn on the grid, snap to it, and create your circle.

[Aligned circle]

The circle is used to align your shape when you rotate it. For our example, let's make the line drawing at the top of the page.

We'll start by doing the best approximation we can using the pen. Note the red vertical line; that's a guide. Right now, we only care about proper alignment for the points that are on the line. For the others, a rough approximation is enough.

[partly aligned drawing]

Now that we've got two points aligned, how do we do the same for the rest? Rotation! First, select both the line and the circle:

[line and circle selected]

Now use Object/Transform/Rotate and enter the amount you want to rotate. Since we're drawing a figure with three-fold rotational symmetry, we'll enter 360/3 = 120 in the Angle box.

[rotation dialog box]

And here's the result.

[off-center line and circle]

Ick! This looks awful. It's really not that bad, though; it's just out of place. To put it back where it was, drag the circle's center control point back to the intersection of the two heavy grid lines. The line will follow with it.

[center line and circle]

Now it's just a matter of repeating the process. Using the direct selection tool, align the points nearest the guide line. When they're in place, select the line and the circle and rotate again. Keep doing that until the shape looks okay.

[symmetric shape]

And there you go: a drawing with perfect rotational symmetry. This can be useful when making knotwork.

Of course, this technique applies to more than line drawings. When it comes to aligning any shape with rotational symmetry, it's almost always handy to create an "alignment dot" in the shape's center. I find it comes in handy when working with stars with an odd number of points.

Note: this technique doesn't work in later versions of Illustrator. Somewhere between Illustrator 7 and Illustrator CS Adobe decided that nobody uses an object's center dot as a handle, so they removed that feature. If you, like me, are one of those nobodies, let me offer you some advice learned the hard way: don't waste effort working around this flaw in Illustrator. Switch to a vector illustration program with better alignment tools. (Suggestions?)

Last updated 4 June 2005
All contents ©1999-2002 Mark L. Irons

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