Using Standard Keyframes

When you played the Blur effect, you may have noticed that the runner turns his head, revealing more of the logo toward the end of the shot. The blurred square remains the same size throughout the segment, so even though it tracks to the correct location, it is too small to hide the entire logo by the end. To solve this type of problem, Media Composer allows you to modify parameters (including the shape) over time using a technique called keyframing. You’ll learn more about advanced keyframing in a later lesson, but in this lesson we’ll use the standard keyframing built into the Effect Preview monitor.

This section picks up where the last one left off, so you should still be on the clip from the last marker, in Effect mode, with the added Blur effect. Under the Effect Preview monitor is a position bar that represents the duration of the segment. Pink triangles located at the start and end of the position bar are called keyframes, which are placed there by default on almost all effects. By selecting the first keyframe, any parameter changes you make are set for only the first frame. Selecting the last keyframe and changing parameters sets the parameter values for only the last frame. Media Composer will then interpolate between the different parameter values to create a smooth animation. You’ll use keyframes to change the shape used for the blur so that it better covers the logo throughout the segment. The shape on the first keyframe is good, so you just need to change the shape on the last keyframe

To use keyframing:

1. In the Effect Preview monitor, select the last keyframe on the far right of the position bar, as shown in Figure 3.24. When you select the last keyframe, the position bar moves to the last frame of the effect, but more importantly, the first keyframe is deselected. Now, using the Reshape tool in the Effect Editor, you can change the shape of the blur to better cover the logo.

Figure 3.24 Triangular keyframes are placed at the start and end of the position bar.

2. Select the RESHAPE tool on the side of the Effect Editor as shown in Figure 3.25; then, in the Effect Preview monitor, drag each of the four corners of the Blur shape to best cover the logo, as shown in Figure 3.26.

Figure 3.25 Select the Reshape tool to correct the blur rectangle.

Figure 3.26 Reshape the rectangle in the Effect Preview monitor to cover the logo.

3. To see how the shape changes from the start of the effect to the end, drag the position bar backward to the start of the segment. To make it easier to know where you are within an effect, the top right of the Effect Preview monitor displays the duration of the effect and the current time within the effect.

4. Using the effect time display, drag the position indicator in the position bar to 1:00 (00:00:29:24 on Master timecode).

Tip: Dragging the position indicator in the Timeline will cause you to exit Effect mode. Use the position bar to move the position indicator within the effect and stay in Effect mode.

The interpolation between the first and last keyframe doesn’t perfectly match the runner’s head turn, so some of the logo appears in this frame. You can add additional keyframes anywhere within the position bar just by changing the shape.

5. In the Effect Preview monitor, drag the top-right and bottom-right corners of the blur shape to best cover the logo, as shown in Figure 3.27. A keyframe is automatically added at the current time.

Figure 3.27 A keyframe is added in the Effect Preview monitor when you drag the rectangle.

6. Using the effect time display, drag the position indicator in the position bar to :23 (00:00:29:17 on Master timecode). At this frame, the runner’s head has not yet turned, so the logo appears much smaller. You no longer need such a big shape, so you can correct the shape on the current frame to automatically create a keyframe.

7. In the Effect Preview monitor, drag the top-right and bottom-right corners of the blur shape to the left to best cover the logo.

8. To see how the shape changes from the start of the effect to the end with the newly added keyframes, drag the position bar backward to the start of the segment.

9. Press the 6 key to play the effect from IN to OUT and review the blur in real time.

Nicely done. You successfully tracked and blurred the logo. You could further refine the blur using feathering in the Effect Editor, but if you want it to be applied across the entire effect, you must now be sure to select all the keyframes in the position bar before making the parameter change.