When you choose Composite from the drop menu, the new object is added to a new
track in the active group, and all layers remain visible in the Canvas simultaneously.
After Composite edit
To composite a layer
Drag an item from the File Browser, Library, or Media list into the Timeline track area.
As you drag, a tooltip appears at the pointer, indicating the frame number where you
When you reach the frame where you want the new layer to start, position the pointer
over the layer you want as the background, holding down the mouse button until the
drop menu appears.
Choose Composite from the drop menu.
The new layer is composited into the project.
Using the Timeline