Graphics Reference
In-Depth Information
dependent. When you draw a vector object, you create one or more lines called a path. A
path is made up of one or more curved or straight line segments. The start and end points
for a line segment is known as an anchor point, which you can drag to change and move.
Illustrator provides drawing tools on the Tools panel that you can use to create a variety
of shapes, including rectangles, rounded rectangles, ellipses, polygons, stars, flares, lines,
arcs, spirals, rectangle grids, and polar (circular) grids. After you draw an object, you can
use Illustrator selection tools to modify it. The two main selection tools are the Selec-
tion tool and the Direct Selection tool. The Selection tool allows you to select entire ob-
jects, while the Direct Selection tool allows you to select paths and segments. In addi-
tion to these tools, you can also use the Select menu. The Select menu provides a variety
of powerful selection commands for you to use in a document or artboard. For example,
you can select objects whose attributes (including Appearance, Blending Modes, Fill &
Stroke, Opacity, and Stroke Color) are similar to the current or last selection.
After you select one or more objects, you can move, align, group, and transform them.
Thetransformationtoolsallowyoutorotate,scale(resize),reflect(mirrorimage),orshear
(slant) an object.
Understanding Vector and Raster Graphics
Illustrator is an application that gives you great control over vector
graphics, which include vector shapes and vector objects. Vector
graphics are created using mathematical shapes, not pixels, and that's
why vector shapes are considered resolution-independent. For ex-
ample, if you enlarge a vector image to 100 times its original size, Il-
lustrator merely changes the mathematical formulas to reflect the new
size, and since vector shapes are constructed of mathematical data in-
stead of pixels, file sizes are extremely small.
Raster graphics, such as bitmaps and photographs, are images creating
using individual pixels that identify one piece of color information.
The reason raster images are considered resolution-dependent is that
once the image is created or scanned, any enlargement of the image
forces Illustrator to enlarge and average the existing color information
in the document. This process, called
interpolation
, is what causes en-
larged raster images to become blurred, or pixelated.
