Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 418

distortion through space. To control the precision of the effect, you can add, delete, or move the points on either
mask. A mask can have an unlimited number of points, but the more points it has, the longer the effect takes to
render. If the distortion appears twisted, try adding more correspondence points at distinguishing points along the
masks. (If the arc lengths of the curves between correspondence points are too different, twisting may result.)
Specifies how After Effects determines the distortion of each video or animation frame in the
Interpolation Method
interval between keyframes or if no keyframes exist.
•
Requires no keyframes because it calculates the distortion at each frame. Discrete produces the most
Discrete
accurate results but requires more rendering time.
•
(Default) Requires two or more keyframes and performs a straight-line interpolation between the
Linear
keyframes. Linear produces steady changes between keyframes and sharp changes at keyframes.
•
Requires three or more keyframes and approximates the distortion using cubic curves, producing distor-
Smooth
tions with graceful motion.
Use the Reshape effect
Open the layer in a Layer panel.
1
Create or import the source, destination, and boundary masks into the layer.
2
Name each mask so that you can easily recognize it in the Mask menu in the Effect Controls panel.
In the Timeline panel, choose None from the Mode pop-up menu for each mask.
3
4 Position the boundary mask to specify the area of the image that will remain unaltered. Areas within the boundary
mask will be distorted; areas outside the mask will remain unaltered. Keep the boundary mask as far as possible from
the source and destination masks to avoid foldovers.
Scale and position the source mask over the image.
5
6 Scale and position the destination mask to indicate the final shape. Distortions work best if the source and desti-
nation masks are in approximately the same location.
Make the Composition or Timeline panel active, select the layer, and then choose Effect > Distort > Reshape.
7
8 From the Mask menus, choose the source, destination, and boundary masks.
Adjust the Percent control, and choose an option for Elasticity.
9
In the Composition panel, add, delete, or move correspondence points on the masks to control the distortion:
10
• To add a point, Alt-click (Windows) or Option-click (Mac OS) the mask.
• To delete a point, Alt-click or Option-click the point.
• To move a point, drag it to a new location.
• To change the interpolation of a pair of points, Shift-click a point. Smooth interpolation works best with round
masks, while linear interpolation works best with angular masks. You can combine smooth and linear interpo-
lation in the same composition.
11 Choose an interpolation method, and preview the distortion. If Linear or Smooth produces undesired results,
add more keyframes. If Discrete produces undesired results, choose another method.
AFTER EFFECTS CS3 412
User Guide