Creating Morph Targets
At the top of the Actions palette is a New Action button. Clicking this button opens a simple dialog box where you can name the new action. Once created, the new action is selected and made active. When an action is active, its current layer is available for editing. You can tell when an object is ready to be edited because the background of the Timeline palette is white and a red arrow points to the active action in the Actions palette, as shown in Figure 21.2.
When an action is active, you can create a new state by editing the existing layer. The edits are remembered as a specific state called a morph target. You can make another action (or the Mainline) active by double-clicking the action in the Actions palette. You can also rename an action by right-clicking it and selecting the Rename option from the pop-up menu.
When the Mainline option in the Actions palette is made active, you can insert any of the available actions by selecting an action and clicking on either the Insert Reference or the Insert Copy buttons. The Insert Reference maintains a link to the original action, so that if the action is edited, the instance is also updated. Deleting an action with the Delete Action button will also delete any referenced instances.
The Insert Copy button places a copy of the action at the current frame. This copy remains unchanged if the original action is edited or deleted.
Adding an action to the current project creates a key at the frame where it is inserted. This key represents an edited state for the layer, and the points in the object will move from the positions in their previous key to their new keyed location over the number of frames separating the two keys. For example, if your default layer is a circle and an action named Square is created where the circle has been edited to be a square, then if the Square action is inserted as a copy at frame 10, the circle points will gradually move to form a square over the first 10 frames of the project.
Using actions, you can morph between different shapes over a designated number of frames. Keep in mind that when creating morph targets, you can only edit the existing points and not add new points to the existing layer. If you want to add new points or objects, you can keep them outside of the working area and then move them within the object for the new morph target.