ProVideo Coalition.com: Creating Motion Graphics: Keyframes by Chris & Trish Meyer

Our next technique involves creating text symbols (bullets, hyphens, and so on), and moving them along a path to indicate the explorer’s route. In the project file, open the MapC-1/setup comp to see this in action.

With the Text tool, we typed some symbols (<-----) that we wanted to move along the route. We copied the Mask Shape from the map layer, then selected the Text layer and pasted the mask. To get the text to follow this path, we expanded the Text > Path Options in the Timeline window, and set the Path popup to Mask 1. Animating the First Margin property in Path Options makes the symbols “link” along the path.

To have text elements follow a mask shape, choose the mask in Text > Path Options > Path, and animate First Margin.

To center the symbols vertically on the path, we selected the text and edited their Baseline Shift in the Character palette (the highlighted value the cursor is pointing at in the figure at right).

To center individual text elements onto the path, edit their Baseline Shift in the Character palette.

Auto-Orienting Objects

Our final option (Map D folder in the accompanying project) involves tracing our explorer’s route by auto-orientating a small boat icon along a motion path. We first created the boat in a precomp by masking a solid layer, then nested this precomp in the MapD-1/setup comp.

We again started by tracing our route on the map layer as before using the Pen tool. We copied this mask shape, and pasted it to the boat layer’s Position property at time 01:00. The trick here is not to simply select the boat layer when you paste, but to explicitly click on the word “Position” in the Timeline so that the Position property receives the path. The mask shape will then become a Position motion path, with a duration of 2 seconds. The first and last mask points appear as linear keyframes, while the intermediate mask points appear as “roving” keyframes (keyframes that have a position in X and Y, but no fixed point in time). We simply dragged the last keyframe later in time to extend the duration of the move.

To make the boat layer automatically rotate along this motion path, we selected Layer > Transform > Auto-Orient and set the Orient Along Path option. The only problem now was that the boat appeared upside down! This was easily fixed by setting Rotation to 180 degrees. Collapse Transformations was enabled for the nested precomp layer so that transformations would be calculated before effects; now the direction of the Drop Shadow is not affected by rotation, as shown in the figures below.

Collapse Transformations renders the rotation before the effects so that the drop shadow retains the same direction no matter how the boat is oriented.

Panning around the Map

If your map is low resolution, you may be able to complete your project in one comp. In our case, we had a tall map and decided to pan around the image using a 2D motion control move - the same technique you’d use to pan around a large photograph (often called the “Ken Burns” effect). This was covered in an old column we wrote called “Anchors Away.” To introduce a little camera shake using The Wiggler or the wiggle expression, refer to our previous column “More Motion, Less Control.” If you want to take this to the next level, try performing a motion control move using the 3D camera and lights!

No matter which technique you use, ease in and out of keyframes for smoother moves, and reduce strobing by enabling Motion Blur for layers that move.

Postscript

After Effects CS3 introduced Shape Layers, which includes a very flexible system for stroking paths including the ability to create dashed lines with custom patterns. You can read an introduction to Shape Layers in our column ”The Shape of Things to Come.” We also discuss Shape Layers extensively in our two books, After Effects Apprentice and Creating Motion Graphics 4th Edition.

Tuesday, November 08, 2005

Map Exploration

Exploring ways to direct a viewer around a map using effects, text animators, and other tricks using Adobe After Effects.