Enabling Motion Blur Effects
Motion blur is an effect that helps the audience identify which objects in the scene are moving fast. When enabled, objects in the scene that are moving are blurred, thereby giving them the impression of speed. Objects in the project that are at rest are not blurred, which gives a contrast to the moving objects.
Motion blur is enabled at the layer level using the Motion Blur panel, shown in Figure 32.1, in the Layer Settings dialog box. To access this panel, double-click a layer or select a layer and click the Layer Settings icon at the top of the Layers palette.
Figure 32.1. The Motion Blur panel in the Layer Settings dialog box.
The Motion Blur On option enables the motion blur effect for the current layer. When enabled, the motion blur effect is created by rendering all the layer objects over a series of frames. These renderings are then combined to create the blurred effect. If the object is moving faster, the distance between each rendered object will be greater than the rendered frames of the slower objects. If the object isn’t moving at all, then the successive frames will appear to be on top of one another.
Note
The motion blur effect is only visible when the project is rendered. It is not visible in the working area.
The Frame Count value sets the number of successive frames that are used to create the blurred object. The default value of 2 is typically enough to give the illusion of motion, but higher values are useful for creating transformation effects.
For objects that aren’t moving that fast, a low Frame Count value results in an effect that is barely noticeable, but you can extend out the successive renderings by causing a designated number of frames to be skipped between the successive frames that are rendered.
Another useful technique that makes the motion blur effect work is to gradually make the trailing renderings transparent. These can be controlled using the Start Opacity and End Opacity values. These values mark the beginning and ending percentages where transparency is introduced and where the fading starts.
The final motion blur parameter is the Blur Radius. This value controls the amount of blur that is applied to the successive renderings. Higher Blur Radius values result in a greater blur effect.
To add a motion blur effect to a layer, follow these steps:
1. | Open the Rocket with motion blur.anme file from the Chapter 32 folder on the CD. This file includes a simple rocket being animated moving over a moonscape surface. |
2. | Select the Rocket layer and open the Layer Settings dialog box. In the Motion Blur panel, enable the Motion Blur On option. Then set the Frame Count to 2, the Frame Skip to 1, the Start Opacity to 50, the End Opacity to 30, and the Blur Radius to 8. This creates a nice blur over two frames. |
3. | Drag the Time slider in the Timeline palette to the middle of the animation and render the project with the File, Preview menu command (Ctrl/Cmd+R). The results are shown in Figure 32.2. |
