Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 273

When you use the Pan Behind tool in the Composition panel, After Effects automatically makes two adjustments. In the Layer panel, the mask
is moved in relation to its layer (top), and in the Composition panel, the layer is moved in relation to the composition (bottom).
Move a mask
Select the mask or masks you want to move.
1
2 In the Composition panel, drag the mask or masks to a new location. To constrain the movement of the mask or
masks to horizontal or vertical, hold down Shift after you start dragging.
Pan a layer behind its mask
Select the Pan Behind tool in the Tools panel
1
Click inside the mask area in the Composition panel and drag the layer to a new position.
2
Apply motion blur to a mask
Motion blur creates a blur based on a mask's movement in the composition. You can apply motion blur to individual
masks. The composition's Enable Motion Blur switch must be selected for any layer or any mask within a layer to
exhibit motion blur.
Motion blur settings for a layer and a composition
A. Enable Motion Blur composition switch B. Motion Blur layer switch
1 Select one or more masks.
Choose Layer > Masks > Motion Blur, and choose one of the following options:
2
The mask will have motion blur only if the layer's Motion Blur switch is selected.
Same As Layer
.
A
B
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