IRBlur
Function
This function is an image-based version of the RBlur
function, using a second image's alpha mask (by default) to control the
amount of radial blurring occurs on an image. This is useful for faking
motion blur effects. In this example, the extremely complex foreground
objects, commonly known as cubes, are rendered on a beach in a 3D package
with the depth information. The 3D image was composited over a background
photo of the beach. A DepthKey
was used to extract a matte of the depth supplied by the 3D render. This
matte was then fed into the second image of the IRBlur to give
a zooming effect.

Parameters
|
Type
|
Defaults
|
Function
|
x/yCenter |
float
|
width/2, height/2 |
The center point of the blur. |
iRadius |
float
|
0 |
The distance from the Center that contains
the blur sample area. |
oRadius |
float
|
width |
The outer edge for the blur area |
aspectRatio |
float
|
1 |
The aspect ratio of the pixels for anamorphic
images. |
damp |
float
|
1 |
A gamma value on the blur |
amplitude |
float
|
.5 |
The amount of blur. This number can also
be negative. |
blurQuality |
float
|
.25 |
The amount of samples. A quality of 1,
the maximum, means 64 samples. |
mirror |
int
|
0 |
This will consider points past the center
area if your amplitude is high enough when it is turned on. |
stepBlend |
float
|
5 |
This controls the blending between the
amount of regions (see below). If you put this at 0, each step will
have a constant blur value. If this is 1, there is a continuous blend
between the different regions. |
steps |
int
|
1 |
This is the amount of regions. The intensity
of the control image is divided up X amount of zones, with X being
equal to regions. If you see stepping between the zones and
stepBlend does not correct it, increase steps to a higher number.
The more steps you use, the slower the process. |
controlChannel |
string
|
"a" |
The channel of the second image
to use to control the amount of sharpen. |
invert |
int
|
0 |
Inverts the controlChannel. |
Synopsis
image IRBlur(
image img,
image controlImg,
float xCenter,
float yCenter
float iRadius,
float oRadius,
float aspectRatio,
float damp,
float amplitude,
float blurQuality,
int mirror,
int steps,
float stepBlend,
const char * controlChannel,
int invert,
);
Script
image = IRBlur(
img,
controlImg,
xCenter, yCenter,
iRadius, oRadius,
aspectRatio,
damp,
amplitude,
blurQuality,
mirror,
steps,
stepBlend
"controlChannel",
invert
);
Command Line
shake -irblur comntrolImg xCenter yCenter iRadius etc....
See Also
RBlur, DepthKey,
About Transformations
and Motion Blur
|