Selected layers that also have properties selected are indicated with a hollow highlight in the Timeline panel. A selected layer that has no properties selected is indicated with a solid highlight.

Top layer selected, but no properties selected; bottom layer selected with properties selected.

To scroll the topmost selected layer to the top of the Timeline panel, press X.

Lloyd Alvarez provides a script on his After Effects Scripts website with which you can tag layers and then select, shy, and solo layers according to their tags. The tags are appended to comments in the Comments field in the Timeline panel.

When you copy (or cut) and paste layers, the layers are pasted so that they appear from top to bottom in the Timeline panel in the same order in which they were selected before the copy (or cut) operation. You can Ctrl-click (Windows) or Command-click (Mac OS) layers to select them in any arbitrary order, cut them, and then immediately paste them to reorder the layers in the order in which they were selected.

Jeff Almasol provides a script on his redefinery website with which you can change the stacking order of layers in a composition by sorting according to In point, Out point, selection order, layer name, or random order.

When you move a layer in space, you modify its Position property.

You can separate the components of a Position property into individual properties—X Position, Y Position, and (for 3D layers) Z Position—so that you can modify or animate each independently. (See Separate dimensions of Position to animate components individually.)

Jeff Almasol provides a script on his redefinery website that places a new null layer on the line between the anchor points of two selected layers; you use a slider control on the null layer to reposition the null layer along this line.

To move selected layers so that their anchor points are at the center in the current view, choose Layer > Transform > Center In View or press Ctrl+Home (Windows) or Command+Home (Mac OS).

To move a layer so that its anchor point is at the center of the composition, right-click (Windows) or Control-click (Mac OS) the Position property, choose Edit Value, choose % Of Composition in the Units menu, and enter 50 for each of the components of the Position property.

To avoid softening of an image that is not moving, make sure that a layer’s Position values are non-fractional values. This avoids resampling that is used when a layer with image quality set to Best is placed on subpixels.

By default, each Position property has two or three components, with each holding the value for one of the spatial dimensions (axes). You can separate the components of a Position property into individual properties—X Position, Y Position, and (for 3D layers) Z Position. Separating dimensions allows you to modify or animate the position of a layer along the x axis, y axis, and z axis independently.

For a video tutorial about using the Separate Dimensions command, go to the Adobe website.

To decompose selected Position properties into individual X Position, Y Position, and (for 3D layers) Z Position properties, do one of the following:

The decision of whether to work with separate dimensions depends on what you’re trying to accomplish. Using one property for position has the advantage of providing smooth motion more easily. Also, using a single property for position enables the use of roving keyframes, which provides uniform speed. Working with separate dimensions for position sacrifices some of this automatic smoothing to gain greater control of spatial animation. Working with separate dimensions also makes some simulations easier, especially in cases in which the simulated forces acting on a layer are orthogonal (perpendicular) to one another.

For example, if you are animating a ball flying horizontally and bouncing vertically, you can do so more easily by separating dimensions. The X Position property can be animated with two keyframes, one for the start position and one for the end position. This horizontal animation represents the speed of the throw. The Y Position property can be animated with a single expression that simulates the acceleration due to gravity and the vertical bouncing from the floor. A similar example is a boat drifting down a river in a variable crosswind.

Use the Align panel to line up or evenly space selected layers. You can align or distribute layers vertically or horizontally.

• To distribute, you must select three or more layers. When Selection is chosen in the Align Layers To menu, you must select two or more layers to align. When Composition is chosen in the Align Layers To menu, you must select one or more layers to align.

• When Selection is chosen in the Align Layers To menu, each alignment option aligns selected layers to the layer that most closely represents the new alignment. For example, for right-edge alignment, all selected layers align to the selected layer with the edge that is farthest to the right.

• A distribution option evenly spaces selected layers between the two most extreme layers. For example, for a vertical distribution option, the selected layers are distributed between the topmost and bottommost selected layers.

• When you distribute layers of different sizes, the spaces between layers may not be uniform. For example, distributing layers by their centers creates equal space between the centers—but different-sized layers extend by different amounts into the space between layers.

• Alignment or distribution options cannot move locked layers.

• The Align panel does not affect alignment of characters within a text layer.

To move selected layers so that their anchor points are at the center in the current view, choose Layer > Transform > Center In View or press Ctrl+Home (Windows) or Command+Home (Mac OS).

Charles Bordenave (nab) provides a script on the After Effects Scripts website, with which you can distribute layers in 3D space.

The beginning of the duration of a layer is its In point, and the end is its Out point. The duration is the span between the In point and the Out point, and the bar that extends from the In point to the Out point is the layer duration bar.

To trim a layer is to modify its In or Out point so that the layer has a different duration. When you trim a layer that is based on moving source footage, you affect which frames of the source footage item are shown in the layer; the first frame to appear is at the In point, and the last frame to appear is at the Out point. Trimming a layer doesn’t cut frames from the footage item; it only affects what frames are played for the layer.

Trimming layers in the Timeline panel

A.

Original In point

B.

Negative layer time indicator for still image layer

C.

Original In point

D.

Slip-edit bar, representing excluded frames for motion footage layer

E.

New In points

When you use a footage item as a source for different layers, you can trim each layer differently to show different portions of the source. Trimming a layer does not alter the footage item or the original source file.

You can trim a layer by changing the In and Out points in the Layer panel or the Timeline panel. (You can also trim a footage item before using it to create a layer. See Create layers from footage items or change layer source.)

The In point , Out point , and duration values for a layer are shown at the bottom of the Layer panel. To show this information for all layers in the Timeline panel, click the In/Out/Duration/Stretch button in the lower-left corner of the Timeline panel. The duration, In point, and Out point for the selected layer are also shown in the Info panel.

In the Layer panel, In and Out points are expressed in layer time. In the Timeline panel, In and Out points are expressed in composition time. The duration is the same in both cases (unless time-remapping or time-stretching is enabled for the layer).

You can extend many kinds of layers for any duration, extending their In points and Out points out past their original times. This capability applies to time-remapped layers, shape layers, layers based on still-image footage items, camera layers, light layers, and text layers. If you extend a layer back in time so that the layer extends into negative layer time (past layer time zero), a series of hash marks on the bottom of the layer bar indicates the portions of the layer that are in negative layer time. This indication is useful if you’ve applied effects to the layer—such as Particle Playground or Shatter—that use layer time to calculate their results.

The layer duration bar represents the layer duration visually. The In, Out, and Duration columns in the Timeline panel represent the layer duration numerically.

These procedures move the entire layer in time.

Jeff Almasol provides a script on his redefinery website with which you can move selected layers as a group, aligning the group to a specific time in the composition.

Use the Sequence Layers keyframe assistant to automatically arrange layers in a sequence. When you apply the keyframe assistant, the first layer you select remains at its initial time, and the other selected layers move to new times in the Timeline panel based on the order in which you selected them.

Layers selected in Timeline panel (top), and layers arranged in sequence by applying the Sequence Layers Keyframe Assistant (bottom)

Overlapping layers can have Opacity keyframes set automatically to create a cross-dissolve.

For a layer to be put into a sequence, its duration must be less than the length of the composition so that it leaves time for other layers. (See Trim, extend, or slip-edit a layer.)

When you copy a layer, you copy all of its properties, including effects, keyframes, expressions, and masks.

Duplicating a layer is a shortcut with which you copy and paste the layer with one command. Duplicating a layer with a track matte preserves the relative ordering of the layer and its track matte.

When you paste layers, they are placed in the order in which you selected them before copying. The first layer selected is the last one to be placed, so it ends up on the top in the layer stacking order. If you select layers from the top first, they end up in the same stacking order when pasted.

If you have a component of a layer—such as a mask or keyframe—selected when you copy, you copy only that component. Before copying, press Shift+F2 to deselect all of the components of a layer and leave the layer itself selected.

When you split a layer, both resulting layers contain all of the keyframes that were in the original layer in their original positions. Any applied track mattes retain their order, on top of the layer.

After you split a layer, the duration of the original layer ends at the point of the split, and the new layer starts at that point in time.

If no layer is selected when you choose Edit > Split Layer, all layers are split at the current time.

Paul Tuersley provides a script on the AE Enhancers forum for splitting layers at layer markers.

Lloyd Alvarez provides a script on his After Effects Scripts website that automatically detects edits in a footage layer and splits it into a separate layer for each edit (or places a layer marker at each edit).

The auto-orientation options (Layer > Transform > Auto-Orient) for each layer specify how its orientation depends on motion paths, points of interest, and cameras.

Off

The layer rotates freely, independent of the motion path, point of interest, or other layers.

Orient Along Path

The layer faces in the direction of the motion path. For example, use this option for a camera to depict the perspective of a driver who is looking at the road ahead while driving.

Orient Towards Camera

The layer is always oriented so that it faces the active camera. This option is available for 3D layers; this option is not available for 2D layers, cameras, or lights. 3D text layers have an additional option, Orient Each Character Independently, which orients each character around its individual anchor point. Selecting Orient Each Character Independently enables per-character 3D properties for the text layer if they aren’t already enabled. (See Per-character 3D text properties.)

Orient Towards Point Of Interest

The camera or light always points at its point of interest. This option is not available for layers other than cameras and lights. (See Cameras, lights, and points of interest.)

The automatic orientation to point to the point of interest occurs before the Rotation and Orientation transformations are applied. To animate a camera or light with the Orient Towards Point Of Interest option to look temporarily away from the point of interest, animate the Rotation and Orientation transform properties.

Dan Ebberts provides an expression on his MotionScript website that auto-orients a layer along only one axis. This is useful, for example, for having characters turn from side to side to follow the camera while remaining upright.