Adobe After Effects CS4 - Manual (Page 315)

309 USING AFTER EFFECTS CS4
Drawing, painting, and paths
Last updated 12/21/2009
More Help topics
“ Creating shapes and masks ” on page 312
“ Add, edit, and remove expressions ” on page 647
About shapes and shape layers
Shape layers contain vector graphics objects called shapes. By default, a shape consists of a path, a stroke, and a fill. (See
“
About paths ” on page 307 and “ Strokes and fills for shapes ” on page 333.)
You create shape layers by drawing in the Composition panel with the shape tools or the Pen tool. (See “ Creating
shapes and masks ” on page 312.)
Shape paths have two varieties: parametric shape paths and Bezier shape paths. Parametric shape paths are defined
numerically, by properties that you can modify and animate after drawing, in the Timeline panel. Bezier shape paths
are defined by a collection of vertices (path points) and segments that you can modify in the Composition panel. You
work with Bezier shape paths in the same way that you work with mask paths. All mask paths are Bezier paths.
You can modify a shape path by applying path operations, such as Wiggle Paths and Pucker & Bloat. You apply a stroke
to a path or fill the area defined by a path with color by applying paint operations. (See “
Shape attributes, paint
operations, and path operations for shape layers ” on page 333.)
Shape paths, paint operations, and path operations for shapes are collectively called shape attributes. You add shape
attributes using the Add menu in the Tools panel or in the Timeline panel. Each shape attribute is represented as a
property group in the Timeline panel, with properties that you can animate, just as you do with any other layer
property. (See “
About animation, keyframes, and expressions ” on page 210.)
The color bit depth of a shape layer is the same as the project as a whole: 8, 16, or 32 bpc. (See “ Color depth and high
dynamic range color ” on page 274.)
Shape layers are not based on footage items. Layers that are not based on footage items are sometimes called synthetic
layers. Text layers are also synthetic layers and are also composed of vector graphics objects, so many of the rules and
guidelines that apply to text layers also apply to shape layers. For example, you can’t open a shape layer in a Layer panel,
just as you can’t open a text layer in a Layer panel.
You can save your favorite shapes as animation presets. (See “ Save an animation preset ” on page 388.)
More Help topics
“ Creating shapes and masks ” on page 312
“ Best practices for creating text and vector graphics for video ” on page 342
Online resources for shape layers
For a video tutorial introducing shape layers, visit the Adobe website at www.adobe.com/go/vid0224 .
Trish and Chris Meyer provide an introduction to shape layers in a PDF excerpt from the “Shape Layers” chapter of
their book
Creating Motion Graphics with After Effects (4th Edition) .
Trish and Chris Meyer also provide a video introduction to shape layers on the ProVideo Coalition website .
You can download additional animation presets that take advantage of per-character 3D text animation from the After
Effects Exchange on the Adobe website.
Chris Zwar provides an animation preset on his website that creates a target cross-hair using a single shape layer, with
a wide variety of custom properties that make controlling and modifying the cross-hair animation easy and obvious.