Animating Shape Layers
After Effects offers a deceptively robust system for creating shapes with Shape Layer. Each layer can hold one or more shapes, and the shape can be heavily modified with custom operations. By animating and layering shapes, you can create geometric motion backgrounds.
There are several ways to create shapes in After Effects. The methods vary to offer you the most choices as you design. There is no right or wrong here; just use the method that suits you best:
- You can create a new shape layer by choosing Layer > New > Shape Layer. Then click the Add button in the toolbar. You can add a Rectangle, an Ellipse, or a Polystar.
- If you choose a shape tool from the toolbar, you can also create a shape by hand. You can draw on a shape layer (just make sure the Tool Creates Shape option is marked in the toolbar). Be sure to hold down the Option (Alt) key if you want to create a path-based shape.
- If no layer is highlighted in the Timeline, just pick the shape you want from the toolbar. Double-click its icon, and a new shape is added to the window.
- You can also copy and paste shapes from Adobe Illustrator as paths into After Effects. See the article at http://tinyurl.com/aepaths for more details.
On the surface, shapes seem pretty simple, but the Polystar is very flexible. The shape can either be a polygon or a star (depending on whether it is concave or convex). You can assign as many sides or points as you want.
When you're happy with the shape, remember that you have precise control over fill and stroke. By default, a shape has a fill and a stroke, but you can choose to use one or both. If you're designing shapes to use as a background, we recommend removing or reducing the stroke and setting the fill to a lower opacity. Multiple shapes can then be better blended.
To further modify a shape layer, you can apply multiple path operations. These can be used individually or combined. The multiple path operations options will be fully explored in Chapter 10, "Designing with Vectors."
For purposes of creating a background, three of the path operations stand out:
Pucker & Bloat. This option pulls the vertices of a path inward or outward (Figure 7.29). It can be used to create dramatically varied shapes from your stars or polygons shapes.
Figure 7.29 The Pucker & Bloat operator works on all shape types to create dramatically different variations.
Wiggle. You can add organic wiggle to the edges of a shape (Figure 7.30). Be sure to adjust the Wiggles/Second property to slow down the effect so it's not too distracting.
Figure 7.30 To create natural, organic motion, use the Wiggle operator.
Twist. This operator rotates a path sharply around the center of an object (Figure 7.31).
Figure 7.31 The Twist operator creates rough patterns.
The Repeater operation seems to have been made for animation. With it, you can easily create multiple copies of a shape and even apply a transformation to each copy. Better yet, those transformations can be keyframed for animation or offset to create cycling copies.
As you work with a repeater, you'll quickly see that it is very efficient. You can create hundreds of copies of an object in your composition yet only one in the Timeline. This speeds up rendering and certainly gives you a leg up on project organization.
- Apply the Repeater operator to a shape layer. By default three copies are added.
- Twirl down the Repeater and Transform Repeater controls in the Timeline.
Adjust the Scale and Position values to create a cascade effect. Each change you make is applied to each copy. For example, an 80% scale is applied to the first copy and the second copy is 80% the size of the last. In this manner the operations compound with one another.
Try adding multiple copies and experimenting with options like Blend Modes and Rotation when creating backgrounds (Figure 7.32).
Figure 7.32 The Repeater operator contains several controls. Be sure to test them out to see the results you can generate. The Repeater provides intuitive feedback and is a control worth exploring.
- Use the Composite option to control the stacking order. If you're making objects larger, we recommend the Above option; for smaller objects, choose Behind.
Keyframe the Offset value to slide the repeated objects along their path (Figure 7.33). This creates an animation that is very simple and elegant. This is a great way to create a repeating pattern.
Figure 7.33 Multiple instances of the Pi symbol are blended into a geometric pattern. By reducing the opacity of the shape and adjusting blending modes, an overlap occurs.
Be sure to experiment with effects as well. The CC Kaleida effect (Figure 7.34) can create elaborate patterns. Other effects like Blurs and Glows (Figure 7.35) also can liven up your patterned background.
Figure 7.34 Multiple shapes animate past each other to create the initial pattern. Then two instances of the CC Kaleida are used to create a kaleidoscope effect.
Figure 7.35 The Offset operator pushes a five-petaled flower through the scene. The shape is combined with a looping background created with the Fractal Noise effect. The background is finished with the CC Radial Fast blur on a blended adjustment layer and a 4-Color Gradient effect for color.