Editor's Toolkit: Using Transitional Wipes with Avid®
The various mattes in the Editor's Toolkits are simply black and white
animations that are used to define transparency in composited video. These
animations do not have built-in alpha channel transparency like the many
full-color effects and transitions in the Toolkits and therefore are slightly more
complex to use.
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A black and white Transition Wipe from an Editor's Toolkit is used in this example to transition from one clip to another. |
To use an overlay matte in Avid® (e.g. Media Composer®):
1. Arrange your clips on the timeline (Figure 1):
* V3: transition wipe matte
* V2: video clip (A-Roll)
* V1: video clip (B-Roll)

Figure 1 - The initial timeline in Avid® Media Composer®.
2. Add a Matte Key to the clip on V3: Tools menu > Effects Palette >
Key > Matte Key.

Figure 2 - Add a Matte Key to the clip on V3.
3. From the Tools menu, select Effect Editor and select the Swap Sources item
(Figure 3). Different applications default to whether black is transparent or
white; Avid happens to uses a film-style analogy, where black areas are
transparent.

Figure 3 - Select the Swap Sources item in the Effect Editor.
4. If you preview the transition, you'll see that it all works, except that
the A-Roll in Video 2 does not show up anymore. To fix this, copy and past the
clip from V2 into a new track on V4 and trim it back so it doesn't cover the
transition. You can do a little more trimming in V2 for neatness (Figure 4), but
this isn't strictly necessary.

Figure 4 - Copy the video clip in V2 and trim to complete the effect.
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