Can be used to make soft edges rougher in Nuke. It applies a noise to semi-transparent alpha regions. Hard edges can be preblurred to create soft edges.

CS_RoughenEdges.tcl

set cut_paste_input [stack 0]
version 10.5 v3
push $cut_paste_input
Group {
 name CS_RoughenEdges1
 help "Adds a noise to semi-transparent alpha. This way all soft edges are roughened. Hard edges shouldn't be affected."
 tile_color 0xcc804eff
 selected true
 xpos 2270
 ypos -2746
 addUserKnob {20 CS_RoughenEdges}
 addUserKnob {26 preblur}
 addUserKnob {41 size_1 l size T Blur1.size}
 addUserKnob {41 filter T Blur1.filter}
 addUserKnob {41 disable_1 l disable T Blur1.disable}
 addUserKnob {26 noise}
 addUserKnob {41 type T Noise2.type}
 addUserKnob {41 size l x/ysize T Noise2.size}
 addUserKnob {41 zoffset l z T Noise2.zoffset}
 addUserKnob {41 octaves T Noise2.octaves}
 addUserKnob {41 nyquist l "clip at Nyquist limit" T Noise2.nyquist}
 addUserKnob {41 lacunarity T Noise2.lacunarity}
 addUserKnob {41 gain T Noise2.gain}
 addUserKnob {41 gamma T Noise2.gamma}
 addUserKnob {26 ""}
 addUserKnob {26 Creator l "" +STARTLINE T "CS_RoughenEdges v1.1 by Christian Schulze - www.christian-schulze.eu"}
}
 Input {
  inputs 0
  name InputAlpha
  xpos 70
  ypos -58
 }
 Blur {
  channels alpha
  size 50
  name Blur1
  xpos 70
  ypos 8
 }
 Dot {
  name Dot1
  xpos 104
  ypos 66
 }
set N1c106000 [stack 0]
 Dot {
  name Dot3
  xpos -6
  ypos 66
 }
set N1c106800 [stack 0]
 Invert {
  channels alpha
  name Invert1
  xpos -40
  ypos 176
 }
push $N1c106800
 Dot {
  name Dot2
  xpos -116
  ypos 66
 }
 Remove {
  name Remove1
  xpos -150
  ypos 104
 }
 Noise {
  inputs 1+1
  output alpha
  size 250
  gain 0.8
  center {2048 1024}
  name Noise2
  xpos -150
  ypos 176
 }
 Clamp {
  channels alpha
  maximum_enable false
  name Clamp2
  xpos -150
  ypos 248
 }
push $N1c106000
 ChannelMerge {
  inputs 2
  operation from
  name ChannelMerge3
  xpos 70
  ypos 241
 }
 Clamp {
  channels alpha
  maximum_enable false
  name Clamp1
  xpos 70
  ypos 320
 }
 Output {
  name Output
  xpos 70
  ypos 398
 }
end_group