shake's IBlur in Nuke

set cut_paste_input [stack 0]
version 5.2100
push $cut_paste_input
Radial {
area {131.5 92 627 477}
softness 0.855
name Radial1
selected true
xpos 281
ypos 709
postage_stamp true
}
CheckerBoard2 {
inputs 0
name CheckerBoard1
selected true
xpos 183
ypos 711
}
Copy {
inputs 2
from0 rgba.alpha
to0 depth.Z
name Copy3
selected true
xpos 183
ypos 800
}
ZBlur {
math linear
size 20
max_size 12
name ZBlur3
selected true
xpos 183
ypos 855
}

or somthing call iFliter