Apple MA434Z/A User Manual - Page 887

Parameters This node displays the following controls in the Parameters tab: xCenter, yCenter The center point of the blur. By default, these parameters are set to width/2, height/2. iRadius The distance from the center that contains the blur sample area. oRadius The outer edge for the blur area. aspectRatio This parameter inherits the current value of the defaultAspect global parameter. If you're working on a nonsquare pixel or anamorphic image, it is important that this value is set correctly to avoid unwanted distortion in the image. damp A gamma value on the blur. amplitude The overall amount of blur. This number can also be negative, to blur away from the viewer, rather than toward the viewer. quality The amount of samples. A quality of 1, the maximum, is 64 samples. mirror Considers points beyond the center area if your amplitude is high enough when enabled. seed When Shake generates a random pattern of values, you need to make sure for purposes of compositing that you can recreate the same random pattern a second time. In other words, you want to be able to create different random patterns, evaluating each one until you find the one that works best, but then you don't want that particular random pattern to change again. Shake uses the seed value as the basis for generating a random value. Using the same seed value results in the same random value being generated, so that your image doesn't change every time you re-render. Use a single value for a static result, or use the expression "time" to create a pattern of random values that changes over time. For more information on using random numbers in expressions, see "Reference Tables for Functions, Variables, and Expressions" on page 941. Chapter 28 Filters 887