Learn how direction lines and direction points shape curves in vector paths, and how they behave differently at smooth and corner points.
When you select an anchor point that connects curved segments in a path, direction handles appear. These handles include direction lines that end in direction points. The angle and length of the direction lines shape the curved segments. Direction lines are visible only while editing the path and don’t appear in the final artwork.
You can adjust direction lines using the Direct Selection tool, Anchor Point tool, or Pen tool. Select one of these tools, select an anchor point to view the direction lines, and then drag the handle to adjust the curve as needed.
How direction lines behave at smooth points
A smooth point always has two direction lines, which move together as a single, straight unit. When you move a direction line on a smooth point, the curved segments on both sides of the point are adjusted simultaneously, maintaining a continuous curve at that anchor point.
How direction lines behave at corner points
A corner point can have two, one, or no direction lines, depending on whether it joins two, one, or no curved segments, respectively.
Corner point direction lines maintain the corner using different angles. When you move a direction line on a corner point, only the curve on the same side of the point as that of the direction line is adjusted.
How direction lines affect curve shape
Direction lines are always tangent to the curve at the anchor points (perpendicular to the curve’s radius). Two key factors control the curve's shape:
- Angle of a direction line: Controls the slope of the curve.
- Length of a direction line: Controls the height or depth of the curve.
You can show or hide anchor points, direction lines, and direction points by selecting View > Show Edges or View > Hide Edges.
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