Apple Shake 4 - Manual (Page 890)

890 Chapter 28 Filters
focusRange
The distance away from the focusCenter, both toward and away from the camera, that
remains unblurred.
steps
The number of steps that the total range is divided between.
stepBlend
The mixing of the different steps. 0 is no mixing and good for getting a feel for your
step ranges. 1 is complete, linear blending.
ZDefocus
The ZDefocus node is identical to the Defocus blurring node, except you can create a
realistic depth of field by using the image’s Z channel. The Z channel usually comes
from a Z-depth 3D render, but of course can also be placed with Shake channel-
swapping tools (Reorder and Copy).
Like ZBlur, this node works best when there is no abrupt overlapping of foreground
objects over background. The foreground elements work fine, but ringing occurs on
the background. If you are developing a shot of this nature, try to split your foreground
into a separate element.
Parameters
This node displays the following controls in the Parameters tab:
xPixels, yPixels
Defines the kernel size for the defocus, in pixels, which produces the general size of the
defocused flaring in the image. Values lower than 3 have no effect. Progressively higher
values are more processor-intensive to render.
channels
Lets you set which channels Shake should defocus. You can choose one or all of the
red, green, blue, or alpha channels. The default is “rgba.”
percent
A slider that lets you mix the modified image and the original image together to
produce a blend of both. By default, this parameter is set to 100 percent, resulting in
100 percent of the modified image being output.