Creating Animations to Use as Cells
You can also use QuickTime movies as cells. For example, you can create an animation
in Motion, render it as a QuickTime movie, and import it into another Motion project to
use as a cell. In general, the same recommendations for creating still graphics apply to
the creation of animation or video clips you intend to use as cells, but there are additional
considerations.
If a clip is retimed in the Properties Inspector or with a Retiming behavior, the effect of
the retiming is carried through to the particle system.
Note: Using a movie as the source cell for an emitter can impact your project’s playback
performance.