Adding Layers Using Insert and Overlay
You can add motion footage to your composition by using tools and techniques commonly found in non-linear editing (NLE) software. Buttons in the Footage panel, for example, allow you to perform insert and overlay edits—both of which add a layer at the current time, although each affects the timeline's existing layers differently.
Figure 4.33 Note the arrangement of the layers before an insert or overlay edit, as well as the position of the current time indicator.
Figure 4.34 After an overlay edit, the new layer is added as the topmost layer at the current time.
In contrast, adding a layer via an insert edit causes the composition's existing layers to shift in time to accommodate the new layer. In other words, if the new layer is five seconds long, all layers after the current time move forward five seconds. If the current time occurs midway through a layer, the layer is split into two layers; the portion after the current time shifts forward (Figure 4.35).
Figure 4.35 After an insert edit, layers after the current time shift forward to accommodate the new layer. One of the layers is split at the edit point, and the portion after the edit point shifts forward.
To set source footage edit points:
Option/Alt-double-click a motion footage item in the Project panel.
The motion footage item opens in an After Effects Footage panel.
To set an In point, cue the current time and click the Set In button .
The In point display and the duration bar reflect the In point you set (Figure 4.36).
Figure 4.36 Cue the current time to the point at which you want the source footage to start, and click the Set In button to set the source In point.
To set an Out point, cue the current time and click the Set Out button .
The Out point display and the duration bar reflect the Out point you set (Figure 4.37).
Figure 4.37 Cue the current time to the point at which you want the source footage to stop, and click the Set Out button to set the source Out point.
To insert or overlay a layer:
Set the current time of the composition to which you want to add the layer.
You can use the Go To Time command, the Time Controls panel, or the current time indicator in the Timeline panel (as described in the section "Setting the Time," earlier in this chapter).
In the Footage panel, set the source footage In and Out points (as described in the previous task).
Make sure the Edit Target section of the Footage panel displays the name of the composition to which you want to add a layer. If the project contains more than one composition, the window displays the currently selected composition.
- In the Footage panel, click either of the following:
Ripple Insert—If you select this option , all other layers will be shifted forward to accommodate the new layer (Figure 4.38).
Figure 4.38 Depending on the type of edit you want to perform, click the Ripple Insert or Overlay button.
Overlay—If you select this option , other layers will retain their current positions in time.
The selected footage is added to the composition as the topmost layer at the current time. Other layers' positions in time will depend on whether you selected an insert or overlay edit.