User`s guide

Chapter 4 Working with Effects and Filters
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When the mask is in the downstream position, the mask does not move when you reposition
the 3D Plane track because the mask is applied after shape positioning takes place. In this
example, the track media was moved so that its edges are seen through the mask.
You can also create rectangular downstream masks using the controls in the Mask tab. Also
see “Masking the Shape” on page 317.
Applying a Mask to a Track
You can use any still or moving image with an alpha channel to mask another image.
The Spline Primitive media type allows you to quickly create spline objects in basic shapes,
including rectangles, circles, stars, arrows, hearts, and medallions. You can drag these
shapes into Mask tracks to quickly create masks or transitions. See “Using Spline Media” on
page 521.
To apply a mask to a still image:
1. Create a new 3D Plane track using one of the following:
• Select Track > New Shape > 3D Plane.
Add 3D Plane button