9.5

7 Creating and Customizing Motion Effects
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Understanding FluidMotion Timewarp Effects
The FluidMotion rendering option for Timewarp effect creates very smooth rendered effects.
FluidMotion uses an interpolation algorithm that creates intermediate images by morphing
the motion across the bracketing images. FluidMotion examines each pixel in the outgoing
image, finds the corresponding pixel in the incoming image, and creates a motion path
between the two that it uses to build the intermediate images necessary to fill out the effect.
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On a Macintosh system, FluidMotion requires significant system resources and rendering
times can be very long. In addition, when you step through a sequence with a Timewarp
effect, your Avid editing application can take a noticeable amount of time to update the
Effect Preview monitor.
FluidMotion can introduce artifacts into the effect, particularly when objects move in front
of or behind other objects, move significantly between one frame and the next, or move into
the image from outside the frame. FluidMotion Edit provides tools to correct artifacts in a
Timewarp effect.
By definition, artifacts appear only in intermediate images that FluidMotion creates. The
bracketing images, whether frames or fields of original material, do not have artifacts. You
use FluidMotion Edit to make corrections either by incorporating motion information from
other parts of the image or clip or by directly manipulating the artifact’s motion vectors.
FluidMotion performs motion estimation based on the original source frames. When you use
the Effect Editor to edit the motion vectors in a FluidMotion effect, the Timeline changes to
a source-frame Timeline. The position indicator under the Record monitor appears green
when you are working in a source-frame Timeline.
FluidMotion Workflow
The typical workflow for using FluidMotion effects is as follows:
1. Use the Blended Interpolated rendering option to set up the initial motion effect.
This lets you quickly set up the ramp rates and time curves you want. Blended
Interpolated is the closest in quality to FluidMotion but takes less time to render.
For more information, see “Understanding Timewarp Effects” on page 210.
2. Render and play the effect.
For more information, see “Basics of Effects Rendering” on page 53.
3. If you want smoother motion, use the Motion Effect Editor to change the effect to
FluidMotion.
4. Render the effect, and look for artifacts in the rendered media.