There are many different ways to set up the After Effects interface and project settings. In order for your project to match the figures, open SeasonsChange_01_Start.aep from the Chapter 13 DVD materials. This file is set up properly for the current project, but it has nothing in it.
After Effects’ native format is .aep, which stands for After Effects Project. All After Effects project files bear that suffix. Throughout this chapter, I’ve included .aep files that correspond to the progression of the project. If you get lost, you can always open one of the files on the DVD to catch up.
Close Photoshop so that all your computer resources can be devoted to After Effects.
An older version of After Effects won’t open a file created in a newer version of the program, so you must have After Effects CS5 to use the .aep files included on the DVD. CS5 runs only on 64-bit Windows systems and Intel-based Macs, so using this latest version of After Effects may require a computer update. Don’t worry: if you have an earlier version, you can follow along without those files, but some of your settings may be different from what is shown in the demonstration.
Figure 13-2: The reduced summer to winter matte painting in Photoshop
Importing the Composition
You need to import the Photoshop composition that will be the basis of the moving matte shot. In order for the names and organization to match what is shown in the figures, you will use the demonstration file on the DVD while working through this chapter. Choose FileImportFile to open the Import File dialog box. Select SeasonsChangeForAE.psd on the DVD, and, in Import As, choose Composition - Retain Layer Size. Click Open, and a second dialog appears. Make sure that in the Import Kind drop-down menu, Composition – Retain Layer Sizes is selected (Figure 13-3). Leave the other options as they are, and click Open.
Figure 13-3: Import File dialog box
Interface Panels
The After Effects interface is divided into panels similar to Photoshop. There are several preset workspaces to choose from at the upper-right in the interface. For this chapter, make sure Standard is chosen from the Workspace drop-down menu 
.
On the left side, in the Project panel, double-click SeasonsChangeForAE. Your interface will now look like Figure 13-4.
Figure 13-4: After Effects panel layout
Let’s look at some important aspects of each of these panels.
The exact location of the panels and which panels are visible depends on how the interface was left from the previous session using After Effects. Because of that, your interface may differ from what is shown in the figures.
The Project Panel
The Project panel holds pointers/links to all the elements that will make up your animation. Make sure you always keep the original files that make up the project on your drive in the same place. In order to keep .aep files small, After Effects references these files and doesn’t store the actual Photoshop files, movies, still images, sound files, or any other outside file associated with the project. After Effects .aep files internally retain only elements created in the program, such as solid layers of color, text, adjustment layers, and intermediate compositions. Everything else is saved as links to outside files.
Compositions, known from here forward as comps, are the containers that hold the elements of your animation and also determine the resolution of your work. SeasonsChangeForAE is the comp you opened in the Viewer panel by double-clicking it.
In the Project panel, all comps are identified by this icon: 
. When you select a comp or layer, After Effects shows information about your selection at the top of the Project panel, including a thumbnail preview of the contents. In this case, you’ll see that the comp is 3672 × 2648 pixels, the size of the Photoshop file you imported (Figure 13-5).
Figure 13-5: Information and preview for any item selected in the Project panel
Just below the comp is a folder called SeasonsChangeForAE Layers. When you click the arrow next to the folder, the arrow reorients facing downward, revealing all the layers that were imported from Photoshop (Figure 13-6).
Figure 13-6: All the layers and comps displayed in the Project panel
The Viewer Panel
Any item you double-click in the Project panel opens in the Viewer panel. This works for comps and for individual layers. When you have a comp open in the Viewer panel, you can add animation and effects to any layers in the comp.
At the bottom of the Viewer panel are two important drop-down menus for working with your comp. First, at far left in the Viewer window, is the Magnification Ratio pop-up, which displays the percentage that you’re zoomed in or out of the Viewer panel. To the right of that is the Resolution/Down Sample Factor pop-up, which displays the resolution of the comp. Resolution is based on how many pixels After Effects is required to compute to display the image. If the magnification ratio is set to 25%, and the resolution is set to Full, the program is computing 16 times as many pixels as are required to produce an accurate representation of the scene at that size. Why? Because at one-quarter size, After Effects is displaying only every fourth pixel; but at full resolution, it’s forced to compute every pixel, or 4 × 4 more pixels than are needed.
Conversely, if the magnification ratio is set to 100% to view the image detail, but the resolution is set to Quarter, the image will look blurry. In general, you’ll want to have the magnification ratio and resolution in synch. After Effects is more responsive and updates are faster with the resolution set lower. However, when you do the final output, After Effects automatically renders at full resolution unless you set it specifically not to do so.
The source Photoshop file for this project is quite large, so set the resolution for the scene to Quarter. For most of this project, you’ll work at a 25% magnification ratio (Figure 13-7). You can, from time to time, look at the scene at full or half res to preview how things are shaping up. When you do, you should adjust the resolution to match.
Figure 13-7: Magnification Ratio pop-up and Resolution/Down Sample Factor pop-up
The Timeline Panel
At the bottom of the interface is the Timeline panel, where layers are keyframed and animated. In the upper-left corner is the current time, displayed in yellow 
. To the left of the Timeline are the layer names, with layer controls on both sides of the layer names (Figure 13-8).
Figure 13-8: Timeline layer names and controls
To the right of the layer names is the Time Graph. Let’s look at the main controls. At the top is a slender gray bar called the Time Navigator that allows you to control how many frames are displayed in the Time Graph. Below that is the Time Ruler, showing the frame numbers. Above the frame numbers is the yellow Current Time Indicator, marking what frame you’re on in the animation. Just below that is the Work Area bar, a thicker gray bar that controls what frames are rendered. Under that are colored Layer Duration bars, showing when each layer is visible. Whenever a layer is selected, its Layer Duration bar is highlighted (Figure 13-9).
Figure 13-9: Time Graph components, with the currently selected layer highlighted
The Tool Panel
Here are three important tools with which you’ll work in both the Viewer and Timeline panels. To the right of the name is the keyboard shortcut to access each tool:
- The Zoom tool (Z)
enlarges and reduces the size of the comp in the Viewer panel. Click with the tool to zoom in; Option/Alt click to zoom out. You can also zoom in and out using Command/Ctrl+ the (+) or (−) key. - The Hand tool (H)
repositions what is displayed in the Viewer and Timeline panel without disturbing the layers. You can also access the tool by holding down the spacebar. - You use the Selection tool (V)
to select, move, and scale layers in the Viewer panel. It does the same thing with keyframes in the Timeline panel.