Each layer has properties, many of which you can modify and animate. The basic group of properties that every layer has is the Transform group, which includes Position and Opacity properties. When you add certain features to a layer—for example, by adding masks or effects, or by converting the layer to a 3D layer—the layer gains additional properties, collected in property groups.
All layer properties are temporal—they can change the layer over time. Some layer properties, such as Opacity, have only a temporal component. Some layer properties, such as Position, are also spatial—they can move the layer or its pixels across composition space.
You can expand the layer outline to display layer properties and change property values.
Most properties have a stopwatch . Any property with a stopwatch can be animated—that is, changed over time. (See About animation, keyframes, and expressions.)
Properties in the Effects property group (effect properties) are also layer properties. Many effect properties can also be modified in the Effect Controls panel.
The SS shortcut is especially useful for working with paint strokes. Select the paint stroke in the Layer panel, and press SS to open the property group for that stroke in the Timeline panel.
The U and UU commands are especially useful for learning how animation presets, template projects, or other animated items work, because they isolate the properties that were modified by the designer of those items.
You can also filter layers in the Timeline panel to show only layers with properties that match a search string. See Search and filter in the Timeline, Project, and Effects & Presets panels.
You can only duplicate some property groups, including shapes, masks, and effects. However, you can’t duplicate top-level property groups such as Contents, Masks, Effects, and Transforms. If you attempt to duplicate a top-level property group, the entire layer is duplicated, instead.
You can copy the current value of a layer property to another layer, even when the original layer contains no keyframes.
If multiple layers are selected and you change a property for one layer, then the property is changed for all selected layers. Sliders, angle controls, and some other property controls are only available in the Effect Controls panel.
To change the units for a property, right-click (Windows) or Control-click (Mac OS) the underlined value, choose Edit Value, and choose from the Units menu. The available units are different for different property types. You can’t change the units for some properties.
You can enter simple arithmetic expressions for property values and other number entries. For example, you can enter 2*3 instead of 6, 4/2 instead of 2, and 2e2 instead of 200. Such entries can be especially useful when incrementing a value by a specific amount from its original value.
After you click inside the angle control, you can drag outside it for more precision.
If the property contains keyframes, a keyframe is added at the current time with the default value.
Alan Shisko provides a video tutorial on his Motion Graphics 'n Such blog shows how to use label colors and multiple selections to rapidly change properties for multiple layers simultaneously.
Charles Bordenave (nab) provides a script on the After Effects Scripts website that sets the properties in the Transform group for selected layers to random values within constraints that you set.
The LockProperties script, available from the After Effects Scripts website, locks only specified properties so that you can prevent accidental changes.
Transformations, such as rotation and scale, occur around the anchor point (sometimes called transformation point or transformation center) of the layer. By default, the anchor point for most layer types is at the center of the layer.
Though there are times when you’ll want to animate the anchor point, it’s most common to set the anchor point for a layer before you begin animating. For example, if you’re animating an image of a person made up of one layer for each body part, you’ll probably want to move the anchor point of each hand to the wrist area so that the hand rotates around that point for the whole animation.
The easiest way to pan and scan over a large image is to animate Anchor Point and Scale properties.
Alan Shisko provides a detailed video tutorial on his website, demonstrating how to create a complex 3D environment from 3D layers, beginning with simple 2D assets. Manipulating layer anchor points is a crucial part of this tutorial.
If you don’t see the anchor point in the Layer panel, select Anchor Point Path from the View menu at the lower-right area of the Layer panel.
Layers of some types, such as text layers and shape layers, can’t be opened in the Layer panel.
Moving an anchor point with the Pan Behind (Anchor Point) tool changes Position and Anchor Point values so that the layer remains where it was in the composition before you moved the anchor point. To change only the Anchor Point value, Alt-drag (Windows) or Option-drag (Mac OS) with the Pan Behind (Anchor Point) tool.
Charles Bordenave (nab) provides a script on the After Effects Scripts website that moves the anchor points of selected layers without moving the layers in the composition frame.
You can set the anchor point to be in the center of the layer content in any of the following ways:
Here are a few uses of this command:
As with other transformations, scaling of a layer occurs around the anchor point of the layer. If you move the anchor point away from the center of the layer, the layer may move when you flip it. Some layers—such as camera, light, and audio-only layers—don’t have a Scale property.
You can scale a layer beyond the composition frame.
For information on scaling exponentially, as with a zoom lens, see Use Exponential Scale to change the speed of scaling.
To flip a layer is to multiply the horizontal or vertical component of its Scale property value by -1. A layer flips around its anchor point.
To activate the Constrain Proportions icon and match the height to the width, Alt-click (Windows) or Option-click (Mac OS) it.
Scaling down a raster (non-vector) layer sometimes causes a slight softening or blurring of the image. Scaling up a raster layer by a large factor can cause the image to appear blocky or pixelated.
The Detail-preserving Upscale effect is capable of scaling up images by large amounts while preserving details in the image.
For more information, see Detail-preserving Upscale effect.
You can choose between bicubic and bilinear sampling for selected layers, which determines how pixels are sampled for scaling and for all transformations applied using the Transform effect.
For more information, see Layer image quality and subpixel positioning.
Adobe Photoshop provides fine control over resampling methods used for scaling of images. For fine control of resampling, you can export frames to Photoshop to change the image size and then import the frames back into After Effects.
Though it's not very well suited for movies, the content-aware scaling feature in Photoshop is very useful for extending and scaling still images. This feature can be useful when repurposing images for wide-screen formats that were created for standard-definition formats.
For a script that scales multiple compositions simultaneously, go to the AE Enhancers forum.
Lloyd Alvarez provides a script on the After Effects Scripts website that scales selected layers to fit the composition frame, and provides options for cropping or letterboxing.
Aharon Rabinowitz provides a video tutorial on the Creative COW website that demonstrates the uses of changing and animating a 3D layer's Scale property, including changing only the z dimension of Scale.
As with other transformations, rotation of a layer occurs around the anchor point of the layer.
To reveal the Rotation property value for selected layers in the Timeline panel, press R.
The first part of the Rotation property value is the number of whole rotations; the second part is the fractional rotation in degrees.
For information on rotating 3D layers, see Rotate or orient a 3D layer.
When you use footage containing audio, the default audio level for playback is 0 dB, meaning that the level is unadjusted in After Effects. Setting a positive decibel level increases volume, and setting a negative decibel level decreases volume.
Double-clicking an Audio Levels keyframe activates the Audio panel.
The VU meter in the Audio panel displays the volume range for the audio as it plays. The red blocks at the top of the meter represent the volume limit of your system.
For more precision in setting audio levels by dragging sliders, increase the height of the Audio panel.
To set the level of the left and right channels together, drag the center slider up or down.
To set the level of the left channel, drag the left slider up or down, or type a new value in the levels box at the bottom of the left slider.
To set the level of the right channel, drag the right slider up or down, or type a new value in the levels box at the bottom of the right slider.
To synchronize changes to layers by assigning one layer’s transformations to another layer, use parenting. After a layer is made a parent to another layer, the other layer is called the child layer. When you assign a parent, the transform properties of the child layer become relative to the parent layer instead of to the composition. For example, if a parent layer moves 5 pixels to the right of its starting position, then the child layer also moves 5 pixels to the right of its position. Parenting is similar to grouping; transformations made to the group are relative to the anchor point of the parent.
Parenting affects all transform properties except Opacity: Position, Scale, Rotation, and (for 3D layers) Orientation.
When parenting layers, helpful text describing alternate parenting behaviors is displayed on the layer bar below the mouse position and in the Info panel.
A layer can have only one parent, but a layer can be a parent to any number of layers in the same composition.
You can animate child layers independent of their parent layers. You can also parent using null objects, which are hidden layers.
You cannot animate the act of assigning and removing the parent designation—that is, you cannot designate a layer as a parent at one point in time and designate it as a normal layer at a different point in time.
When you create a parenting relationship, you can choose whether to have the child take on the transform property values of the parent or retain its own. If you choose to have the child take on the transform property values of the parent, the child layer jumps to the parent’s position. If you choose to have the child retain its own transform property values, then the child stays where it is. In both cases, subsequent changes to the transform property values of the parent are applied to the child. Similarly, you can choose whether the child jumps when the parenting relationship is removed.
When parenting layers, you can use the Shift key to move the child layer to the location of the parent. This can be useful when you want to attach a layer to a null, but have the layer move to the location of the parent null (for example, attaching a 3D text layer to a null layer created from the 3D Camera Tracker).
To show or hide the Parent column in the Timeline panel, choose Columns > Parent from the Timeline panel menu.
Paul Tuersley provides a script on the AE Enhancers forum for duplicating a parent layer and all of its children, preserving the parenting hierarchy.
Carl Larsen provides a video tutorial on the Creative COW website that demonstrates how to use expressions and parenting to relate the rotation of a set of wheels to the horizontal movement of a vehicle.
Robert Powers provides a video tutorial on the Slippery Rock NYC website that demonstrates the use of parenting and the Puppet tools to animate a character.
To assign a parent layer, but keep that layer from being a visible element in your project, use a null object. A null object is an invisible layer that has all the properties of a visible layer so that it can be a parent to any layer in the composition. Adjust and animate a null object as you would any other layer. You use the same commands to modify settings for a null object that you use for a solid-color layer (Layer > Solid Settings).
You can apply Expression Controls effects to null objects and then use the null object as a control layer for effects and animations in other layers. For example, when working with a camera or light layer, create a null object layer and use an expression to link the Point Of Interest property of the camera or light to the Position property of the null layer. Then, you can animate the Point Of Interest property by moving the null object. It is often easier to select and see a null object than it is to select and see the point of interest.
A composition can contain any number of null objects. A null object is visible only in the Composition and Layer panels and appears in the Composition panel as a rectangular outline with layer handles. Effects are not visible on null objects.
The anchor point of a new null object layer appears in the upper-left corner of the layer, and the layer is anchored in the center of the composition at its anchor point. Change the anchor point as you would for any other layer.
If a null object is visually distracting in your composition frame, consider dragging it out of the frame, onto the pasteboard.
Andrew Kramer provides a video tutorial on his Video Copilot website that demonstrates the use of a null object to animate a 3D stroke.
You can create guide layers from existing layers to use for reference in the Composition panel, to help you position and edit elements. For example, you can use guide layers for visual reference, for audio timing, for timecode reference, or for storing comments to yourself.
A guide layer icon appears next to the name of a guide layer or its source in the Timeline panel.
By default, guide layers aren’t rendered when you create output but can be rendered when desired by changing the render settings for the composition.
Guide layers in nested compositions can’t be viewed in the containing composition.