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In the next example, clicking the Make Compositing Parent button () on track 3 forces the track below (at the same compositing level) to be rendered in 3D and composited as a 2D image.

Track 4 (green-and-gray checkerboard) now has the appearance of depth—the checkerboard tapers to a vanishing point—but is inserted in the composited output as a 2D image at a depth of zero on the Z axis. Track 2 is still rotated in 3D space.

In the next example, clicking the Make Compositing Parent button () on track 3 again forces the track below (at the same compositing level) to be rendered in 3D and composited as a 2D image. However, in this case, the 3D rotation that was applied as parent motion on track 1 is not applied to tracks 3 and 4.

In the next example, all tracks are compositing parents. The 3D track on track 2 is on top, the 2D track in track 3 is composited below track 2, and the 3D track in track 4 is composited below tracks 3 and 4.

Creating masks

Masks are used to create overlays, limit the effects of a filter, and to create transparent titles. In their simplest form, masks work by making a particular color in an image or video transparent. More complex effects can be created with gradients (smoothly blending transparent areas together) and by altering the sensitivity of the mask.

CHP. 14

USING VIDEO FX, COMPOSITING, AND MASKS