Creating the first element: an audio starburst

The first component begins with an audio file, the sound track for the final piece. By applying an effect, you create a visual display of the audio file, which pulsates in perfect synchronization with the sound track. When you add an Adobe Illustrator file, the pulsating starburst appears through the transparent areas of this image.

Importing the footage file

Although the footage files are an Adobe Illustrator and an audio file, the process is the same as for any of the footage files you've imported for earlier lessons. However, this time you'll use the Import Multiple Files command, which requires fewer mouse actions than using the File > Import > File command, especially when you import many files.

1.	Choose File > Import > Multiple Files to open the Import Multiple Files dialog box. Or, press Ctrl + Alt + I (Windows) or Command + Option + I (Mac OS).
2.	Select the Starburst.ai file in your _ai folder, and click Open (Windows) or Import (Mac OS). The dialog box disappears momentarily.
3.	When the Import Multiple Files dialog box reappears, go to your _audio folder and select Soundtrack.aif. Then click Open (Windows) or Import (Mac OS).
4.	When the dialog box reappears, click Done.

Both items appear in the Project window, and they are currently selected. Click any empty area of the Project window to deselect them.

Examining the footage files

You can use the Footage windows to review footage files without placing them in compositions. The Starburst.ai file image is large and appears as black-on-black, so you'll use techniques that make it easily visible. Also, you'll play the audio file in the Footage window.

1.	In the Project window, double-click the Starburst.ai file.
2.	Press Ctrl + - (hyphen) (Windows) or Command + - (hyphen) (Mac OS) to reduce both the magnification and window size so that you can see the entire image area. You may need to press this keyboard shortcut combination more than once. Note Be sure to use the hyphen key in this shortcut, not the minus sign on the numeric keypad.
3.	Click the alpha-channel button at the bottom of the Footage window so that you can see the shape of the artwork. When you are ready to continue, close the Footage window. Alpha-channel button
4.	In the Project window, double-click the Soundtrack.aif file. The Footage window opens as a small playbar. Footage window for audio
5.	Press the play button ( ) in the Footage window to hear the audio, which starts quietly and then grows louder. When you are ready to continue, close the window.

Organizing the project

Although this project uses only two source files, you'll practice good habits of organization that can help when you do complex projects of your own. This means creating folders for the Project window.

1.	Choose File > New > New Folder, or click the folder icon ( ) at the bottom edge of the Project window.
2.	Type ai files for the name, and press Enter or Return.
3.	Drag the Starburst.ai file into the ai files folder and expand the folder so that you can see the item inside. Make sure that nothing is currently selected.
4.	Choose File > New > New Folder again.
5.	Type audio files to name the new folder, and press Enter or Return.
6.	Drag the Soundtrack.aif file into the audio files folder and expand the folder so that you can see the item inside.

Creating a composition

You'll use a preset option to set options quickly for this composition.

1.	Choose Composition > New Composition.
2.	Type Starburst Comp in Composition Name.
3.	For Preset, select NTSC D1 Square Pix, 720 x 540 in the pop-up menu. After Effects automatically fills in the next four settings: Width: 720 Height: 540 Pixel Aspect Ratio: Square Pixels Frame Rate: 29.97
4.	(Optional) In Resolution, select Half or lower, as needed for your system.
5.	In Duration, type 800 to specify eight seconds, and then click OK.

Adding footage to the composition

Next, you'll add the audio file to the composition and preview it within the composition. You'll also change the default audio-preview time limitation.

1.	Move the current-time marker to 0:00, select Soundtrack.aif in the Project window and drag it into the Timeline window.
2.	Choose Composition > Preview > Audio Preview (Here Forward) to preview the audio, or press the decimal key (.) on the numeric keypad. The audio preview plays to 4:00 and then stops.
3.	Choose Edit > Preferences > Previews to open the Preview Preferences dialog box.
4.	Under Audio Preview, type 800 in Duration to change it from four seconds to eight seconds. Then click OK.
5.	Press the decimal key to preview again. You can now hear audio for the entire length of the composition.

Create a new solid and add a mask

Next, you'll create a new solid layer and add a circular mask to this solid. You'll use the results in the next procedure to apply an effect.

1.	If necessary, choose Composition > Background Color, select black, and click OK.
2.	Choose Layer > New > Solid.
3.	In the Solid Settings dialog box, choose the following settings: Type Audio Spectrum in Name. (This is also the name of one of the two effects that you'll apply to this layer.) Click Make Comp Size, or type 720 in Width and 540 in Height. Under Color, click the color swatch to open the color picker and select black. Or, select the eyedropper tool and click any black item in the After Effects interface.
4.	Click OK to close the Solid Settings dialog box.
5.	In the Timeline window, select the Audio Spectrum layer.
6.	In the Tools palette, select the oval mask tool. You may have to press the rectangular mask tool and drag to select the oval mask tool from the pop-up display.
7.	Beginning approximately at the center of the solid, start to drag and then press Ctrl + Shift (Windows) or Command + Shift (Mac OS) to draw from the center and constrain the shape to a circle. Drag without releasing the mouse button until the circle is approximately one-eighth the size of the composition (about 90 pixels).

Applying the Audio Spectrum effect

You'll now generate an animated element with the Audio Spectrum effect. This is a visual effect that links a graphical representation of sound frequencies to a path. You'll use the path you drew in the previous procedure so that lines representing the sound radiate in and out from a single point on the path.

1.	With the Audio Spectrum layer selected, press M to reveal the Mask Shape property.
2.	Expand the Soundtrack.aif layer outline by clicking the arrows next to the layer name, Audio, and Waveform. The graphic representation of the audio levels appears in the timeline. To increase the vertical proportion of the waveform display, move the pointer to the faint white line below the lower waveform until it turns into a double-headed arrow ( ). Drag downward to stretch the waveform display, as shown below.
3.	In the Switches panel, click the Quality switch for the Audio Spectrum layer to set it at Best ( ).
4.	Set the current time to about 5:00. (The audio is loud at this point, making it easier to see the results as you apply the effect.)
5.	Make sure that the Audio Spectrum layer is still selected and then choose Effect > Render > Audio Spectrum.
6.	In the Effect Controls window, change only the following settings: For Audio Layer, select Soundtrack.aif in the pop-up menu. A row of vertical green lines appears in the Composition window, representing the frequencies of the audio layer. For Path, select Mask 1. The green lines now radiate from the circular path. For Start Frequency, scrub or type 1.0. For End Frequency, scrub or type 5667. For Frequency Bands, scrub or type 117. For Maximum Height, scrub or type 31000. For Audio Duration (Milliseconds), scrub or type 180. For Thickness, scrub or type 6. For Softness, scrub or type 100%. For both Inside Color and Outside Color, select white. Select Blend Overlapping Colors. Deselect both Dynamic Hue Phase and Color Symmetry. For Display Options, select Analog Lines and notice the changes in the image.
7.	Make sure that the following remain at the default settings: Start and End Point (values are irrelevant in this case). Audio Offset (at 0). Hue Interpolation (at 0). Side Options (Side A & B). Duration Averaging (not selected). Composite on Original (not selected).
8.	When all other options are set, select Use Polar Path (near the top of the list of options) so that the display radiates from one point along the circular path.
9.	Collapse the Audio Spectrum effect.
10.	In the Timeline window, close the waveform for the Soundtrack.aif layer, set the Quality switch for the Audio Spectrum layer back to Draft, and create a RAM preview. Note Depending on the amount of RAM available to After Effects, you may also need to drop the resolution of the composition to see the entire RAM preview in close to real time.
11.	Save the project.

You have now created a graphical representation of the audio frequencies in the Soundtrack.aif layer. As a result, you have an animated image (the Audio Spectrum layer) synchronized with the audio. At the beginning, the layer image is small but it increases in size and intensity as the audio grows louder and more complex.

Some of the settings for the Audio Spectrum effect determine how After Effects calculates the lines for the display. Other settings determine visual properties of the lines themselves. For a description of each of these controls, see the Effects documentation available on the After Effects 5.0 Classroom in a Book CD and on the Adobe Web site for After Effects, in the in-depth section under After Effects product information. For general information and sample images showing examples of the Audio Spectrum effect in action, see After Effects online Help.

Applying the Radial Blur effect

You'll now apply another effect to the Audio Spectrum layer. The Radial Blur effect creates smoother lines by blurring the graphic image of the audio. In this procedure, you'll also learn how to override the size limitation of a slider in the Effect Controls window by setting that option in the Timeline window.

1.	With the current-time marker at about 5:00, select the Audio Spectrum layer, if it is not already selected, and press E to open the Effects properties in the Timeline window.
2.	Choose Effect > Blur & Sharpen > Radial Blur. The Radial Blur effect is now listed below the Audio Spectrum effect in the Effect Controls window.
3.	Expand the Radial Blur effect in both the Timeline and Effect Controls windows so that you can see the Amount value in both windows. In the Effect Controls window only, expand the Amount to see the graphical preview and slider. You can drag the slider only as high as 118, but you can set higher values in the Timeline window.
4.	In the Timeline window, type or scrub to set the Amount value at 160. (Notice that in the Effect Controls window, the arrow points beyond the right end of the slider.)
5.	For Type, select Zoom to create a blur that pulls into the center. Do not change the Center coordinates or the Antialiasing (Best Quality) option, which is set at Low by default.
6.	In the Switches Panel, set the Quality switch to Best ( ).
7.	In the Composition window, set the Resolution to Full to see the layer with full antialiasing so that you can see the results of the blur.
8.	Lower the Resolution and Quality settings, if necessary for your system, and then preview the animation.
9.	Close the Effect Controls window. In the Timeline window, click the arrow to collapse the layer-properties outline. Save the project.

Moving the mask

Next, you'll nudge the mask into position in the center of the Audio Spectrum image. If you drew the Mask 1 path so that it is centered in the composition frame, this procedure is not required. However, you should try this in any case, to learn how to move the mask within the layer instead of moving the entire layer.

1.	Move the current-time marker to about 5:00, so you can see rays representing the audio track.
2.	Select the Audio Spectrum layer.
3.	Press M to open the Mask 1 Mask Shape property. The yellow path appears in the Composition window.
4.	In the Timeline window, select Mask 1. Four solid-yellow handles appear, representing the path points.
5.	Using the selection tool (), click one of the yellow handles or anywhere along the yellow line and then drag the path to the approximate center of the frame. It is not necessary to be precise. When you finish, press M to hide the Mask property.

Adding the starburst image and applying a transfer mode

You're now ready to add the Adobe Illustrator file to the composition. You'll use a transfer mode so that the graphic display of the audio appears through the alpha channel of the starburst image.

1.	Move the current-time marker to 0:00.
2.	In the Project window, select the Starburst.ai file, drag it to the Timeline window, and place it in the Layer 1 position. If it appears at some other layer number, you can drag it by its name to the top of the layer stack. Note This image is black artwork with an alpha channel, so you won't see its shape in the Composition window when you add it to the composition. It will also cover the Audio Spectrum layer, so you won't see that layer until you set the transfer mode.
3.	Move the current-time marker to approximately 3:00 (where the Audio Spectrum layer would not be completely black), so that you'll be able to see it behind the Starburst.ai layer when you set the transfer mode.
4.	Click Switches/Modes at the bottom of the panel in the Timeline window to open the Modes panel. Or, choose Panels > Modes in the Timeline window menu.
5.	In the Modes panel, choose Stencil Alpha for the Starburst.ai layer to set the transfer mode.
6.	Move the current-time marker to 0:00, preview the animation, and then save the project.

Audio Spectrum layer (left), alpha channel of the Starburst.ai layer (center), and Stencil Alpha transfer mode applied to relate the Audio Spectrum layer and Starburst.ai layer (right)

The Starburst.ai layer now acts like the holes in a stencil: You can see the Audio Spectrum layer only through the transparent areas of the Starburst.ai layer alpha channel.

Rotating the starburst image

You'll now set Rotation keyframes for the starburst image so that it spins as the Audio Spectrum layer pulsates behind it, seen through the starburst alpha channel.

1.	In the Timeline window, move the current-time marker to 0:00 and select the Starburst.ai layer.
2.	Press S to open the Scale property, and then scrub or type 50% to reduce the image size by half.
3.	Press R to open the Rotation property.
4.	Make sure that the Rotation value is set to 0° and then click the Rotation stopwatch () to set a keyframe.
5.	Press End to move the current-time marker to 7:29.
6.	Change the Rotation value to 90°. A second keyframe is added.
7.	Move the current-time marker back to 0:00 and preview the animation. Then save the project.

Rendering the starburst element

You have finished building the starburst element, so it's time to render the composition.

1.	Close the Composition, Timeline, and Effect Controls windows for Starburst Comp.
2.	In the Project window, select Starburst Comp and then choose Composition > Make Movie.
3.	In the Output Movie To dialog box, type Starburst.mov in Name and specify the _mov folder in the AE_CIB job folder. Then click Save.
4.	In the Render Queue, click the underlined words Current Settings to open the Render Settings dialog box.
5.	Use the following Render Settings: For Quality, select Best. For Resolution, select Full. For Time Span, select Length of Comp. Then click OK to close the Render Settings dialog box.
6.	In the Output Module pop-up menu, choose Custom to open the Output Module Settings dialog box, and set the following options: For Format, select QuickTime Movie. Select Import into Project When Done. Click Format Options.
7.	In the Compression Settings dialog box, select Animation and Millions of Colors+, and then click OK.
8.	In the Output Module Settings dialog box, review the settings: Channels is now set to RGB + Alpha, indicating that this item will be rendered with an alpha channel. Depth is set as Millions of Colors+, and Color is set as Premultiplied (Matted). When you are ready to continue, click OK. Note You'll render this composition as a silent movie, so do not select options for audio output. The sound track will be added to the final project at a later stage.
9.	Save the project one more time, and then click Render.

When the rendering process is complete, close the Render Queue and double-click Starburst.mov in the Project window to view the rendered movie.

If you need to make any changes, reopen the Starburst Comp and make those adjustments. Remember to save those changes and render the composition again, using the same render settings.