|The pen tool is an incredibly powerful addition to Adobe Photoshop that opens up the door to working beyond bitmap images. Instead of working with images based on pixels, the pen tool creates graphics defined mathematically, also known as vector images. Because vectors are based on mathematical properties they are resolution independent, meaning you can stretch them or zoom in infinitely without losing any detail. Try doing this to a bitmap image! |
Vector objects are defined in Photoshop with paths. Paths are outlines of an object that can be made up of straight segments, curved segments, or a combination of the two. The segments are connected by anchor points, which define the relationship between the segments. Each anchor point in a curved segment (these segments are called Bezier curves) has one or more control handles, which define the shape of the curve on either side of that point. Making the control handles longer or shorter manipulates the strength of the effect of the handles, while rotating the control handles changes the angle of the curve to match the angle of the handle. There are two types of anchor points, which connect path segments in different ways. A smooth anchor point creates curves that are tangent to each other ó in other words they enter and leave the point at the same angle to create a smooth transition. The second type is a corner anchor point. These connect segments in a way that is not smooth and marks a sharp change in direction (this type of anchor point is also used to connect straight lines).
Letís open up the pen tool palette and see what tools we are given to work with. Click and hold the mouse button on the Pen Tool in the Tools Palette to bring up the other pen tools. You will see five tools here: the Pen Tool, Freeform Pen Tool, Add Anchor Point Tool, Delete Anchor Point Tool, and Convert Point Tool. The Pen Tool is the base tool for this set ó it is used to create the path point by point. The Freeform Pen Tool lets you quickly create paths by drawing it with the mouse; Photoshop will then create a path based off your freeform shape. The Add Anchor Point and Delete Anchor Point tools are used to add and delete the points between line and curve segments in paths. The Convert Point Tool allows you to change an anchor point between a smooth anchor point and a corner anchor point.
The most basic path that you can create is a simple straight line. To do this select the Pen Tool, click to place the first anchor point, click somewhere else to place another anchor point, and youíve created a line! Additional clicks create additional line segments attached to the previous point. To draw a curved line, instead of simply clicking to create an anchor point you must click and drag to define the control handles. While creating a path you can alternately switch between straight line and curved segments by clicking, or clicking and dragging to create points with or without control handles.
There are two additional tools that can be used in the editing of paths. These can be found on the tool palette located directly above the pen tool and are the Path Component Selection tool and the Direct Selection tool. The Direct Selection tool will select an entire path, while the Path Component Selection tool selects individual parts of a path (the anchor points, segments and control handles). The selected path or path components can then be moved or edited in many of the same ways that bitmap graphics can be manipulated, including copying, pasting, scaling, and skewing.
So now that you have a path, what can you do with it? Clicking on the paths tab (next to the layers and channels tabs) shows you some of your options. You can create a selection out of your path (you can also create paths out of selections), fill in the path with a color, or stroke your path using the last selected brush.
Paths are best understood by playing around with them, so get out that pen tool and start practicing!
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