Enabling Frame Skipping

When you click the Play button, the defined animation will play back as closely as it can to the specified frame rate, but if the scene is complex—particularly if it has a lot of particles—then the real-time display in the main window may take more computing power than it has time to display. If this happens, the timing of the animation will fail as the computer struggles to display the scene as created.

To solve this problem, the Animation menu includes an option to Allow Frame Skipping. With this menu option enabled, the display will automatically drop any frames that it can’t render in time to keep a consistent frame rate. This affects the display quality, but it maintains the timing of the animation.

To enable frame skipping, follow these steps:

1.	Open the American flag.anme file from the Chapter 16 folder on the CD. This file includes a vector layer of the American flag. With all the stars, this layer has a lot of points and animating it will cause the playback to slow down. The flag has been animated moving and rotating about the working area, as shown in Figure 16.3. Figure 16.3. Animated American flag. [View full size image]
2.	Use the File, Project Settings command to open the Project Settings dialog box and set the frame rate to 12 and close the dialog box. Then click the Play button in the lower-left corner of the main window to see the resulting animation. With a low frame rate, the animation plays back slowly and the display has no trouble keeping up.
3.	Open the Project Settings dialog box again and change the frame rate to 120. Then click the Play button again. This time the animation plays faster, but it’s more jumpy and erratic, and the stars seem to be falling behind.
4.	Select the Animation, Allow Frame Skipping menu command and notice the change. The animation plays back without the jumpy, erratic motion because some of the frames are being skipped. At this high frame rate, the skipped frames won’t even be noticed.