Convolve – Apple Shake 4 User Manual
Page 865
Chapter 28
Filters
865
Shake’s Blur is one of the few nodes that can deactivate the Infinite Workspace —its
“spread” parameter gives you the choice of blurring pixels inside or outside of the image
boundaries. If your final image appears clipped and you aren’t sure why (for example,
you haven’t applied any Crop commands), go back and check the Blur node spread
parameter. Toggle the spread parameters to Outside Frame (1), and the clipping should
disappear.
For more information on the Infinite Workspace, see “
Taking Advantage of the Infinite
Parameters
This node displays the following controls in the Parameters tab:
xPixels, yPixels
The amount of blur as described in pixels, for example, entering a value 200 blurs 200
pixels to either side of the current pixel. By default, yPixels is linked to xPixels.
spread
Tells Shake whether or not to consider outside of the frame. A button to the right of
the parameter name lets you set the mode.
•
0 = Compute “In Frame Only.”
•
1 = Compute “Outside Frame.”
Because of the Infinite Workspace, it is sometimes handy to compute outside of the
frame as well, for example, if the Blur is placed after a Scale command. Note that if
nothing is outside of the frame (black), you see a black edge.
xFilter, yFilter
Lets you pick which method Shake uses to transform the image. For more information,
see “
Filters Within Transform Nodes
channels
Lets you set which channels Shake should blur. You can choose one or all of the red,
green, blue, or alpha channels. The default is “rgba.”
Convolve
The Convolve node allows you to define your own custom filter using a convolution
kernel. Standard filters are available in your include/nreal.h file, and appear in the kernel
pop-up menu in the Parameters tab. The included kernels define the following filters:
•
blur3x3: 3 x 3-pixel blur
•
blur5x5: 5 x 5-pixel blur
•
sharpen
•
edge3x3: 3 x 3-pixel edge detection
•
edge5x5: 5 x 5-pixel edge detection
•
laplace: edge detection
•
smoothedge: another type of edge detection