Some Background Information

Animated backgrounds are used in just about every area of video postproduction. You see them all the time behind “talking heads”, as part of DVD motion menus, as the foundation of interstitial graphics on TV (e.g. “here’s what’s coming up next”), and as elements in complex motion design pieces. In After Effects 7.0 we include an entire set of Background Animation Presets, which make it easy to get started, but it really isn’t hard to create your own animated backgrounds from scratch if you learn a few basic concepts.

The first thing you need to know is how to manipulate the Fractal Noise effect in After Effects, which is by far the most useful effect for creating animated backgrounds. To start off, create a new composition in the format of your choice (my examples below are in NTSC DV) and make its duration 5 seconds. Then add a new solid to your comp by going to Layer>New>Solid, and in the Solid Settings dialog click the “Make Comp Size” button. It doesn’t matter what color it is, just go ahead and click OK.

Then apply the Fractal Noise effect by going to Effect>Noise & Grain>Fractal Noise and your comp will look like this:

fractalnoise_1.jpg

Next, to animate the noise, set an initial keyframe for the Evolution property by clicking on it’s stopwatch icon in the Effect Controls panel. If you can’t see the Effect Controls panel, hit the F3 key on your keyboard to reveal it.

fractalnoise_2.jpg

Then, hit the End key on your keyboard, which will bring your Current Time Indicator to the last frame on your timeline. Turn the Evolution dial in the Effect Controls clockwise 2 rotations, which will animate the noise 2 cycles over the duration of the comp. To preview the animation, go to Composition>Preview>RAM Preview.

Not too interesting, eh? Well, that’s just the starting point. By learning how to manipulate the controls in Fractal Noise, and then adding some complimentary effects, you can achieve an incredibly wide range of looks. For starters, go back to the Effect Controls and pull down the Fractal Type menu at the very top of the effect. Try selecting each of the options and doing a RAM Preview to get an idea of the basic look of each. Once you’ve finished, select Dynamic Twist (which will look like fig 1. below).

fractalnoise_3.jpg

Next, you’ll make the noise more abstract by lowering its complexity. In the Effect Controls, click on the setting for Complexity (the default is 6.0) and change it to 3.0 (figure 2, above). Next, to stretch it out and make wavy lines, twirl down the Transform property in the Effect Controls by clicking on the triangle to the left of its name. Uncheck the Uniform Scaling checkbox, and set Scale Width to 600 (figure 3) and Scale Height to 35 (figure 4).

Now RAM Preview again to see the results. Quite different from where we started out, eh? And the best part is the animation is the result of just 2 keyframes set on the Evolution property.

In order to make this more interesting, we’re going to apply 3 complementary effects: Levels, Fast Blur, and CC Toner. Levels (which works the same way as Levels in Photoshop) will let us adjust the brightness & contrast with a great degree of control, Fast Blur will make the background more abstract, and CC Toner will let us colorize the final result.

First, apply Levels by going to Effect>Color Correction>Levels. By moving the 3 triangles below the Histogram, you can adjust your black and white levels, as well as the gamma. Move the triangles so they’re about where I have them below.

fractalnoise_4.jpg

You can see the result is much different from the Fractal Noise effect by itself. Try playing with the sliders below the Histogram to see what kind of looks you can get, then go back to the settings in the figure above.

Apply the Fast Blur by going to Effect>Blur & Sharpen>Fast Blur. Set the Blur Dimensions to Horizontal, click the Repeat Edge Pixels checkbox, and increase Blurriness to 300 by clicking & dragging on its value to the right, which will allow you to see the adjustment in the Composition Viewer as you make it.

Then add some color to your animation by going to Effect>Color Correction>CC Toner. Click the color swatch for Midtones, and select a vibrant blue color.

fractalnoise_5.jpg

Finally, RAM Preview to see your finished animated background. Experiment by changing the Fractal Type, tweeking the Levels settings, blur amount, and mapping different colors in CC Toner.

Most of the Background Animation Presets in AE7 use this formula, or a variant thereof. Since the Presets are just a stack of effects & keyframes, applying them and then “looking under the hood” to see how they were created is a good insight into how to create more varied backgrounds. A good keyboard shortcut is “UU” (i.e. hit the letter U key on your keyboard twice in rapid succession) which shows you what properties on a layer have been modified from their default settings. By applying a Background Animation Preset, then hitting the F3 key to reveal its Effect Controls, then hitting the UU keyboard shortcut, you can get a good overview of how the preset was constructed. Then to see how it was animated, hit the “U” key on your keyboard which will reveal on the timeline only the properties that have keyframes. The example I just took you through is very similar to the “Red Speed” Background Animation Preset in AE7.

If you create an animated background that you really like, save it as a preset for future use by dragging the effects & keyframes from the timeline to the Effects & Presets panel. You’ll get a dialog asking you to name your new preset, and then it’s yours to use again and again (or share with others).