Apple MA434Z/A User Manual - Page 829

For example, if you want to isolate a warping operation to a particular region, you can create a closed boundary shape to lock off just that area. Sometimes, you may have to use several concentric rings of boundary shapes to completely lock down an area of the image. You can also use open boundary shapes to "pin down" specific areas of an image that you don't want to be affected by a warping effect. For example, if you were creating a warp effect to manipulate an animal's face, you could use a combination of open and closed shapes and single-point shapes to prevent the eyes and nose from being affected by the warp you're applying to the eyebrow area. Open boundary shapes Closed boundary shape Note: By default, the outer edge of the frame is also used as a boundary shape, by default. This behavior can be disabled by turning off the addBorderShape parameter in the Parameters tab for the Warper or Morpher node you're adjusting, but this may produce unexpected results. Isolating the Subject of Deformation Prior to Warping or Morphing Even when you use one or more boundary shapes to pin down areas surrounding a warp effect, you may find that some of the surrounding image is still affected, however slightly. For this reason, it may be useful to isolate the subject of the image prior to using either the Warper or Morpher node. Ideally, the subject of the warp effect was shot against bluescreen or greenscreen, and can be keyed. If not, you can always rotoscope the image using a RotoShape node. In either case, the Warper and Morpher nodes affect the alpha channel of the image along with the RGB portion, so you can always add either node to the tree after you've isolated your subject by keying or rotoscoping. This way, you can add a clean background no matter how extreme the warping effect is. Chapter 27 Warping and Morphing Images 829