Understanding Motion and Keyframes A key part of creating the Retro Titles Effect is the use of motion. Motion is one of the effects in Premiere Elements that you can control with keyframes. Video clips are made up of frames. Keyframes are the key points in a clip where something significant, or "key," happens, such as when a video clip changes size, speed, direction, or opacity, for example, or when an audio clip changes volume. The Motion Effect For the purposes of this effect, we want to create motionin other words, we want to animateboth the actors' stills and the credits. To do this, we are using Premiere Elements' Motion effect, which is a default effect for every visual media on the Timeline, including video clips, stills, and titles. To animate a clip, you first set a start point (assigning the x, y coordinates as explained earlier in this chapter), an end point (again assigning the x, y coordinates), and one or as many middle points as are needed. Each point is defined using a keyframe and each keyframe marks the frame where a change takes place. You don't need to set keyframes or set the x, y coordinates for every frame in a clip, however. Premiere Elements takes care of the "in between" changes for you. This is known as tweening, a term that comes from the animation (cartooning) world (as does the term keyframe). For example, if you have a keyframe that has the clip starting in the lower left corner of the screen and a keyframe that has the clip ending in the upper right corner, Premiere Elements will "tween" (in other words, or provide us with) all of the changes to the clip for the intervening frames across the screen.
You can control the motion and timing of a clip using a combination of dragging the clip in the Monitor panel to define the motion, and setting keyframes and entering numeric values in the Properties panel to define the timing. Controlling the Timing of a Clip In the preceding example, the speed at which the clip travels diagonally across the screen is uniform for the given duration of the clip. If we want to speed up or slow down how the clip moves at any point, we can add additional keyframes. How far apart or close together these keyframes are controls how fast or slow the clip plays.
You can also view and manipulate keyframes right on the Timeline. Keyframes are gold when selected and gray when not. You navigate from keyframe to keyframe and add and delete keyframes in the Timeline the same way that you do in the Properties panel. Using keyframes on the Timeline is best suited for Opacity changes and Volume changes (for audio clips). For example, if near the end of the clip we were to add another keyframe at the middle of the screen, then the clip will be take a relatively long time to move from the left corner to the center of the screen, after which it would rocket from the center to the upper right. If, on the other hand, we set this third keyframe very near the end of the clip and very near the upper right corner, the clip would rocket immediately to the upper right, and then take a relatively long time to go from that point to the end frame in the upper corner. |