Apple Motion 2 - Manual (Page 247)

Chapter 3 Basic Compositing 247
The Preserve Opacity Option
The Preserve Opacity checkbox allows you to limit an object’s visibility to areas of the
Canvas where it overlaps nontransparent regions of other objects. For example, you
might place two overlapping objects into your project, as shown below:
If you turn on Preserve Opacity for the Dolphin object on top, the result is this:
The only area of the Dolphin object that is visible is the area that overlaps the sea life
picture object underneath. At first, this may not appear to be very exciting, but the
Preserve Opacity checkbox can be used in combination with the opacity and blend
mode to create some very interesting effects.
Note: The object with the enabled Preserve Opacity takes the opacity value of the
object beneath it in the composite stack.
01112.book Page 247 Sunday, March 13, 2005 10:36 PM