About direction lines and direction points

Before you draw and modify curved segments with the pen tool, it's important to understand two elements that are associated with control points on curves. When you select a control point connecting curved segments, the segments display direction lines that end in direction points. The angle and length of the direction lines determine the shape and size of the curved segments. Moving the direction points reshapes the curves. Direction lines are for your reference, and don't appear on your Web page.


After selecting a control point (left), direction lines appear on any curved segments connected to it (right).

A smooth point always has two direction lines that move together as a single, straight unit. When you drag the direction point of either direction line on a smooth point, both direction lines move simultaneously, maintaining a continuous curve at that control point.

In comparison, a corner point has no direction lines. The angles of corner points are changed by dragging the corner point directly.


Adjusting direction lines on a smooth point (left) and a corner point (right)

Direction lines are always tangent to (perpendicular to the radius of) the curve at the control points. The angle of each direction line determines the slope of the curve, and the length of each direction line determines the height, or depth, of the curve.


Moving and resizing direction lines changes the slopes of curves.