Shape attributes, paint operations, and path operations for shape layers

After a shape layer has been created, you can add attributes—paths, paint operations, and path operations—by using the Add menu in the Tools panel or in the Timeline panel.

By default, the new attributes are inserted into the selected shape group or groups according to the following rules:

• New paths are added below existing paths and groups.

• New path operations—such as Zig Zag and Wiggle Paths—are added below existing path operations. If no path operations are present, new path operations are added below existing paths.

• New paint operations—strokes and fills—are added below existing paths and above existing strokes and fills.

To override these rules and place a new attribute at the end of the group, below all attributes, hold the Alt (Windows) or Option (Mac OS) key as you click to choose an item from the Add menu.

The Repeater operation is always added at the end of the group.

Strokes and fills for shapes

Strokes and fills for shapes are paint operations that add colored pixels to a path or to the area defined by a path. A stroke or a fill can consist of a solid color, or it can use a gradient of colors. Strokes can be continuous, or they can consist of a periodic series of dashes and gaps. Each stroke and fill has its own blending mode, which determines how it interacts with other paint operations in the same group.

By default, paint operations within a group are performed from the bottom to the top in the Timeline panel stacking order. This means, for example, that a stroke is rendered on top of (in front of) a stroke that appears after it in the Timeline panel. To override this default behavior for a specific fill or stroke, choose Above Previous In Same Group for the Composite property for the fill or stroke in the Timeline panel.

New shapes are created with fill and stroke properties depicted by the swatch buttons next to the underlined Fill and Stroke text controls in the Tools panel. You can also modify the fill colors, stroke colors, fill type, and stroke type for selected shapes using these controls. The Fill and Stroke controls are only visible in the Tools panel when a shape layer is selected or a drawing tool is active.

If multiple shapes are selected, with different fill or stroke properties, then the swatch button next to the Fill or Stroke control contains a question mark. You can still modify the fill and stroke properties using these controls, and the corresponding properties for all selected shapes are set to the same value.

Fills and strokes can be any of four types:

No paint operation is performed.

The entire fill or stroke consists of one color.

The fill or stroke consists of colors and opacity values defined by a linear gradient and then mapped onto the composition along a single axis from the Start Point to the End Point.

The fill or stroke consists of colors and opacity values defined by a linear gradient, which are mapped onto the composition along a radius extending outward from the Start Point at the center to the End Point at the circumference of a circle. You can offset the starting point by modifying the Highlight Length and Highlight Angle values.

The colors of strokes and fills for shape layers are not rendered as high-dynamic range colors. Color values under 0.0 or over 1.0 are clipped to fall within the range of 0.0 to 1.0.

Choose stroke or fill type and blending options

• To choose a fill type or stroke type for new shapes, or set the blending mode or opacity for a fill or stroke for new shapes, click the underlined Fill or Stroke text control in the Tools panel. To cycle through fill types or stroke types for existing shapes, select the shapes before using these controls.
• To cycle through fill types or stroke types for new shapes, Alt-click (Windows) or Option-click (Mac OS) the swatch button next to the underlined Fill or Stroke text control in the Tools panel. To choose a fill type or stroke type for existing shapes, select the shapes before using these controls.

Choose a solid color or edit a gradient for a stroke or fill

• To choose a solid color or gradient for fills or strokes for new shapes, click the swatch button next to the underlined Fill or Stroke text control in the Tools panel. To choose a solid color or gradient for fills or strokes for existing shapes, select the shapes before using the controls.

Modify the color mapping for a gradient

A gradient is a range of color and opacity values that you can customize in the Gradient Editor dialog box. You can also customize how those colors are applied to a stroke or fill by modifying the Start Point and End Point, which determine the direction and scale of the gradient. For example, you can modify these points to stretch the colors of a gradient over a larger area, or orient a linear gradient so that colors fade from top to bottom instead of from left to right. For a radial gradient, you define the center of gradient, its radius, and the offset of a highlight.

By default, when you create a shape path by drawing with the Pen tool, the control points for the gradient are placed in the center of the layer. You can adjust these points after you finish drawing.

You can modify the Start Point, End Point, Highlight Angle, and Highlight Length properties in the Timeline panel. You can also modify these properties directly in the Composition panel.

Set stroke width

• To set stroke width for new shapes in pixels (px), drag the underlined Stroke Width control (which is located to the right of the Stroke controls in the Tools panel), or click the control and enter a value in the box. To set the stroke width for existing shapes, select them before using the Stroke Width control.

Create a dashed stroke

You create a dashed stroke by adding any number of dashes and gaps to the Dashes property group for the stroke. The dashes and gaps in this property group are repeated as many times as necessary to cover the entire path. The Offset property determines at what point on the path the stroke begins.

Line Cap options for strokes

The Line Cap property for a dashed stroke determines the appearance of the ends of the stroke segments (dashes).

The stroke ends at the end of the path.

The stroke extends beyond the end of the path for a number of pixels equal to the stroke width in pixels. The cap is a semicircle.

The stroke extends beyond the end of the path for a number of pixels equal to the stroke width in pixels. The end is squared off.

Line Join options for strokes

The Line Join property for a stroke determines the appearance of the stroke where the path suddenly changes direction (turns a corner).

A pointed connection. The Miter Limit value determines the conditions under which a beveled join is used instead of a miter join. If the miter limit is 4, then when the length of the point reaches four times the stroke weight, a bevel join is used instead. A miter limit of 1 causes a bevel join.

A rounded connection.

A squared-off connection.

Fill rules for shapes

A fill operation works by painting color in the area defined as inside a path. Determining what is considered inside a path is easy when the path is something simple, like a circle. However, when a path intersects itself, or when a compound path consists of paths enclosed by other paths, determining what is considered inside is not as easy.

After Effects uses one of two rules to determine what is considered inside a path for the purpose of creating fills. Both rules count the number of times that a straight line drawn from a point crosses the path on its way out of the area surrounded by a path. The nonzero winding fill rule considers path direction; the even-odd fill rule does not.

After Effects and Illustrator use the nonzero winding fill rule as the default.

If a line drawn from a point in any direction crosses the path an odd number of times, then the point is inside; otherwise, the point is outside.

The crossing count for a line is the total number of times that the line crosses a left-to-right portion of the path minus the total number of times that the line crosses a right-to-left portion of the path. If a line drawn in any direction from the point has a crossing count of zero, then the point is outside; otherwise, the point is inside.

Because the nonzero winding fill rule takes path direction into account, using this fill rule and reversing the direction of one or more paths in a compound path is useful for creating holes in compound paths.

Taper shape strokes

You can also taper the start and end points, and the size of the tapering of your shape strokes to give your animations a fluid and polished look. For more information, see How to taper shape strokes.

Alter shapes with path operations

Path operations are similar to effects. These live operations act nondestructively on a shape’s path to create a modified path that other shape operations (such as fills and strokes) can apply to. The original path is not modified. Because path operations are live, you can modify or remove them at any time. Path operations apply to all paths above them in the same group; as with all shape attributes, you can reorder path operations by dragging, cutting, copying, and pasting in the Timeline panel.

Merge Paths options

The Merge Paths path operation takes all of the paths above it in the same group as input. The output is a single path that combines the input paths. The input paths are still visible in the Timeline panel, but they are essentially removed from the rendering of the shape layer, so they don’t appear in the Composition panel. A fill and stroke are added after the Merge Paths property group in the Timeline panel if a fill and stroke are not already present; otherwise, the output path wouldn’t be visible.

The Merge Paths path operation has the following options, each of which performs different calculations to determine the output path:

Merges all input paths into a single compound path. This option is the default used for shapes created from text characters made up of multiple paths, like the letter e, when using the Create Shapes From Text command.

Creates a path that encompasses the union of the areas of the input paths.

Creates a path that encompasses only the areas defined by the topmost path, subtracting the area defined by underlying paths.

Creates a path that encompasses only the areas defined by intersections between all input paths.

Creates a path that is the union of the areas defined by all input paths, minus the areas defined by intersections between all input paths.

Using the Repeater to replicate shapes

The Repeater path operation creates virtual copies of all paths, strokes, and fills above it in the same group. The virtual copies are not represented by separate entries in the Timeline panel, but they are rendered in the Composition panel. Each copy is transformed according to its order in the set of copies and the values of the properties in the Transform property group for that instance of the Repeater.

If the original shape is numbered 0, the next copy is numbered 1, and so on, then the result of the Repeater is to apply each transformation in the Transform property group n times to copy number n.

Consider the example of the Repeater applied to a shape with the Copies value set to 10 and the Position property in the Transform property group for the Repeater set to (0.0, 8.0). The original shape remains in its original position, (0.0, 0.0). The first copy appears at (0.0, 8.0), the second copy appears at (0.0, 16.0), the third copy appears at (0.0, 24.0), and so on, until the ninth copy at (0.0, 72.0), for a total of ten shapes.

You can apply multiple instances of the Repeater within the same group. In other words, you can repeat the Repeater. Using multiple instances of the Repeater is an easy way to create a grid of virtual copies of a single shape: just set the Position property for one instance of the Repeater to modify the horizontal values, and another instance to modify vertical values.

The Offset property value is used to offset the transformations by a specific number of copies. For example, if the Copies value is 10 and the Offset value is 3, then the original shape is transformed by 3 times the amount specified in the Transform property group, and the last copy is transformed by 12 times the amount specified in the Transform property group.

The Composite option determines whether copies are rendered above (in front of) or below (behind) the copies that precede them.

Use the Start Opacity value to set the opacity of the original shape, and the End Opacity value to set the opacity for the last copy. Opacity values for copies in between are interpolated.

If you place the Repeater after a path, above the fill and stroke property groups for a shape, then the set of virtual copies is filled or stroked as a compound path. If you leave the Repeater below the fill and stroke, then each copy is filled and stroked individually. The difference is most apparent with gradient fills and strokes.

Chris Zwar provides an example project on his website that uses the Card Dance effect and a shape layer with the Repeater operation to simulate a halftone color separation for any image or video.