Understand paths and shapes in InDesign

Types of paths and shapes

You can create paths and combine them in a variety of ways in InDesign. InDesign creates the following types of paths and shapes:

Simple paths

Simple paths are the basic building blocks of compound paths and shapes. They consist of one open or closed path, which may be self-intersecting.

Compound paths

Compound paths consist of two or more simple paths that interact with or intercept each other. They are more basic than compound shapes and are recognized by all PostScript-compliant applications. Paths combined in a compound path act as one object and share attributes (such as colors or stroke styles).

Compound shapes

Compound shapes consist of two or more paths, compound paths, groups, blends, text outlines, text frames, or other shapes that interact with and intercept one another to create new, editable shapes. Some compound shapes appear as compound paths, but their component paths can be edited on a path-by-path basis and do not need to share attributes.

Types of paths and shapes
Types of paths and shapes

A. Three simple paths B. Compound path C. Compound shape 

About paths

As you draw, you create a line called a path. A path is made up of one or more straight or curved segments. The beginning and end of each segment are marked by anchor points, which work like pins holding a wire in place. A path can be closed (for example, a circle), or open, with distinct endpoints (for example, a wavy line).

You change the shape of a path by dragging its anchor points, the direction points at the end of direction lines that appear at anchor points, or the path segment itself.

Components of a path
Components of a path

A. Selected (solid) endpoint B. Selected anchor point C. Unselected anchor point D. Curved path segment E. Direction line F. Direction point 

Paths can have two kinds of anchor points: corner points and smooth points. At a corner point, a path abruptly changes direction. At a smooth point, path segments are connected as a continuous curve. You can draw a path using any combination of corner and smooth points. If you draw the wrong kind of point, you can always change it.

Points on a path
Points on a path

A. Four corner points B. Four smooth points C. Combination of corner and smooth points 

A corner point can connect any two straight or curved segments, while a smooth point always connects two curved segments.

Corner points
A corner point can connect both straight segments and curved segments.

Opomba:

Don’t confuse corner and smooth points with straight and curved segments.

A path’s outline is called a stroke. A color or gradient applied to an open or closed path’s interior area is called a fill. A stroke can have weight (thickness), color, and a dash pattern (Illustrator and InDesign) or a stylized line pattern (InDesign). After you create a path or shape, you can change the characteristics of its stroke and fill.

In InDesign, each path also displays a center point, which marks the center of the shape but is not part of the actual path. You can use this point to drag the path, to align the path with other elements, or to select all anchor points on the path. The center point is always visible; it can’t be hidden or deleted.

About direction lines and direction points

When you select an anchor point that connects curved segments (or select the segment itself), the anchor points of the connecting segments display direction handles, which consist of 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 don’t appear in the final output.

Anchor points
After selecting an anchor point (left), direction lines appear on any curved segments connected by the anchor point (right).

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.

In comparison, 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 by 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 direction line is adjusted.

Anchor points
After selecting an anchor point (left), direction lines appear on any curved segments connected by the anchor point (right).

Adjusting direction lines
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 anchor 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
Moving and resizing direction lines changes the slope of curves.

Opomba:

In Illustrator, you can show or hide anchor points, direction lines, and direction points by choosing View > Show Edges or View > Hide Edges.