#40 Using Motion Guides
When you tween an object from one location on the Stage to another, the tweened object moves in a straight line. If you want the object to follow a more interesting path, you can use a motion guide to steer it.
To create a motion guide:
- Motion-tween an object from one point to another. (Motion guides don't work with shape tweens.) It doesn't matter where the object starts and ends; you'll adjust that later.
- Select the layer in the Timeline that contains the tweened object, and click the Add Motion Guide icon (Figure 40a). A new layer appears, with the layer you selected indented beneath it.
Figure 40a The Timeline looks like this when it contains a guide layer.
The new layer's icon indicates that it's a specialized type of layer called a guide layer. The layer containing your tweened object has become a guided layer.
- Select the empty keyframe at the beginning of the guide layer.
- On the Stage, draw the path you'd like the tweened object to follow. You can draw it with any tool, but the Pencil or Pen is recommended.
Drag the tweened object to one end of the motion guide and snap it to the guide (Figure 40b).
Figure 40b The registration point of a symbol instance is marked with a white circle. Grab the instance by that circle, and drop the circle precisely onto the motion guide.
The snapping maneuver is tricky. Try to drag the object by its registration point and drop it a short distance inward from the beginning of the path.
- Drag the playhead to the last keyframe of the tween and snap the object to the other end of the motion guide.
- Scrub through or preview the movie. Instead of traveling in a straight line, the tweened object should follow the motion guide. If it doesn't, try repeating steps 5 and 6 a few more times.
- By default, the tweened object maintains the same orientation no matter where it moves along the path. If you'd prefer that the object vary its orientation, always staying perpendicular to the portion of the path it's on, select Orient to Path in the Property inspector.