Tóm Tắt
#26 Drawing in Perspective
As with any new feature, Perspective Drawing brings with it new tools, new behaviors, and new limitations that you need to become familiar with to work effectively.
One basic challenge is keeping track of which plane you’re drawing on. Fortunately, Adobe added a hard-to-ignore element—the Active Plane Widget—at the top left of the document that appears whenever the perspective grid is visible (Figure 26a). The highlighted side of the cube shown in the widget indicates the currently active plane.
Figure 26a The Active Plane Widget in its various modes (top row, left to right): Left Grid, Right Grid, Horizontal Grid (or ground plane), and No Active Grid. Below each is the cursor’s appearance when drawing objects on that grid.
All but one of Illustrator’s object drawing tools work with the Perspective Drawing feature (Figure 26b): the Flare tool is not supported. With the perspective grid visible and the desired plane active, simply choose any other object drawing tool and start drawing. All shapes will be drawn in the perspective of the active plane.
Figure 26b Rectangles, ellipses, polygons, stars, arcs, spirals, rectangular and polar grids, and live, editable type can all be drawn in perspective.
What the Perspective Drawing Feature Isn’t
Illustrator is not a 3D modeling environment. Its Perspective Drawing feature provides no camera angle that can be changed, no surfaces to be mapped, and no means of controlling light or shadows. The perspective grid is basically a static framework on which you can draw and add shapes and text that will conform to that grid.
Once you set up your grid and start drawing on it, you’re committed. You can’t remove an object drawn on or added to the grid and return it to its “normal” state. Nor can you change the vanishing point or other aspects of the grid itself and have the artwork that’s already on it adapt to those changes.
Plan out your perspective drawing before you get started and keep your expectations for the feature in… well, perspective. Knowing its limitation will help you take advantage of what it does well.
Moving or modifying objects already in perspective requires switching to the new Perspective Selection tool 
(Shift-V). Use this tool to scale objects in perspective, not the Scale tool. Using Illustrator’s standard selection or transformation tools will break any object’s connection to the grid and expand its appearance. Fortunately, Illustrator displays a prominent warning every time you run this risk (Figure 26c).
Figure 26c A useful warning dialog box prevents you from ruining your perspective drawing if you attempt to modify an object with the wrong tool.
Working Smarter in Perspective
Perspective Drawing is a great new feature that’s actually easier to use and more flexible when it’s combined with older Illustrator features. In the following example, we’ll combine Perspective Drawing with symbols, clipping masks, and transparency to make the feature appear to do things it can’t actually do.
Fast Plane Switching
To switch quickly between different planes on the perspective grid, remember these shortcuts. Pressing the 1 key activates the left plane; 2 activates the horizontal (or ground) plane; 3 activates the right plane; and 4 exits Perspective Drawing, setting the widget to “no active grid.”
These keyboard shortcuts also help you move selected objects from one plane to another. Hold down the mouse and select any perspective object, then tap a number key to move the object onto that plane. To copy an object to another plane, hold down the Option (Alt) key before pressing one of the shortcut numbers.
Holding down the 5 key while moving an object moves it perpendicular to its current plane.
Once an object is in perspective, it can’t be removed from the grid and reverted to its flat state. Because of this it’s important to work with symbols as much as possible (Figure 26d). Symbols used on the perspective grid are just placed instances, so you can modify the original symbol as flat artwork, then see all instances on the grid update in perspective.
Figure 26d These three symbols were used to build the finished illustration in Figure 26i.
Figure 26e The stars and stripes symbol is placed into perspective on the left plane.
Figure 26f A rectangle drawn in perspective over the stars-and-stripes symbol and converted to a clipping path crops the pattern to create one side of the box.
A symbol is a single object, making it easier to select and position on a perspective grid. The stars-and-stripes pattern mapped to the left plane in Figure 26e is one symbol made up of multiple objects. Symbols can be easily contained within a clipping mask, as in Figure 26f.
No Live Perspective for the Pen Tool
Perspective Drawing does not support one of Illustrator’s most-used tools: the Pen tool. The easiest way to work around this is to draw your pen-based artwork off the perspective grid, then select it with the Perspective Selection tool and move it onto the active grid.
Type and Perspective
Live, editable text can be added to the perspective grid only after it’s been typed. The text must be selected with the Perspective Selection tool and dragged onto the appropriate plane. To modify text that’s already on the perspective grid, double-click it with the Perspective Selection tool to enter Isolation mode, where you can work exclusively on the text. Once you’ve modified your text and exited Isolation Mode, the text is re-rendered in perspective.
By combining symbols and clipping masks, you can simulate art that wraps around an object, which is something the Perspective Drawing feature can’t do (Figure 26g).
Figure 26g We copied the clipped symbol to the right plane, positioning it within the clipping mask to match up with the pattern on the left plane and create a wrap-around effect. We drew a black, semi-transparent rectangle with a multiply blend mode on the left plane to create a sense of depth.
Figure 26h We added the gift tag and shadow symbols from Figure 26d to the right plane, and created the ribbon by drawing rectangles on both planes.
Figure 26i The finished perspective art. A gradient-filled rectangle drawn in perspective on the ground plane simulates a cast shadow. We added the bow at the top and the string on the tag off the perspective grid.
Do Your Rotating Off the Grid
You can’t rotate shapes or symbols once they’re on the perspective grid. If you want to rotate an object in perspective, you’ll have to draw it off the grid, rotate it, switch to the Perspective Selection tool, and then move the rotated artwork onto the grid.
The Stroke Problem
Perspective drawing creates the illusion of 3D, but that illusion is shattered if your artwork contains strokes. Perspective drawing does not support strokes. If very thin strokes are used, it may not be a significant problem, but the heavier the stroke weight, and the farther back along the grid the stroked object appears, the worse the effect looks. To work around this shortcoming, convert the stroke to a shape (Object > Path > Outline Stroke) before putting the object in perspective.
