Apple Shake 4 - Manual (Page 899)

Chapter 29 Optimizing and Troubleshooting Your Scripts 899
Use the SetDOD Node to Reduce Rendering Time
This node limits the portion of the image the renderer needs to concentrate on, as well
as quickly masks off a large portion of the image. SetDOD optimizes memory, IO
activity, and render times. In this example, even though the only interesting portion of
the image is the ball in the middle, Shake inefficiently has to consider the entire image.
To limit the area Shake must consider, apply a Transform–SetDOD node to optimize the
render.
Problems With Premultiplication
Most noticeable problems with premultiplication fall into two basic categories:
• Unwanted fringing appears around keyed or masked subjects.
• Color-correction or filtering nodes affect parts of an image they’re not supposed to.
To resolve these issues, you must follow two specific rules about premultiplication.