Friday, December 10, 2010

Vectors Explained

As you know, Photoshop is primarily known for its ability to manipulate pixels, those tiny building blocks that join together so tightly that they seem to form a smooth image, usually a digital photograph. But Photoshop is also handy with the other important family of computer-graphics building blocks: the little guys called vectors.

Vectors are lines, whose curvature, thickness, and length are determined by mathematical formulae. You don’t need to know any math; it’s all done for you. If you want a shape like a circle, your job is to simply draw the circle; Photoshop defines the center point and the radius to create a circle. At that point, you can specify the circle’s color, line thickness, and so on.

It might seem odd to find vector-drawing tools in a pixel-pushing program like Photoshop; vector drawing is usually associated with very different programs, like Illustrator and Freehand. Photoshop can’t create entire vector documents. It uses vector elements and stores them in layers and as paths.  But be grateful that Photoshop offers this feature; it can come in handy in a number of situations. Most commonly vectors are used for cutting something out from its background in a photograph. Check out the car, vectors were used to cut it out.
The pen tool is great for these kinds of cutout tasks because of the clean, controllable, reusable nature of vectors.

Other times you might prefer to use Photoshop’s vector tools are for a large poster, because you can create it small and then scale it up huge without losing any quality. Vectors are great for when you have to change a design many times because you get no degradation each time you change something. Vectors also work great for text and box heavy designs such as postcards, because the edges will print nice and sharp.
In Photoshop (and other Adobe programs), the mathematical name for the lines that determine vectors is Bézier curves.
They’re named after their French creator, Pierre Bézier, who came up with a clever way to make computer-drawn lines bend to their will. A Bezier curve’s direction and angle is determined by the position of little anchor points that lie nearby
 Here are all the different parts that make up a curve. A path is a series of curves joined together.
Notice as you click a point it changes color and becomes black. This is called “filled or selected” you can now modify this portion of the path.


Post a Comment