CompStart

Pro Lessons Courses Elements Software

Grain Check

ToolSets / Utility

Utility

2026-09-07

ToolSets/utility/grainCheck.nk

utility

grain

noise

cineon

difference

check

View on GitHub

Isolates grain and noise by differencing a Cineon plate against a slight blur, then lifting the residual for review.

Grain Check shows high-frequency grain and noise so you can judge plate texture without guessing from the full image.

It converts the input to Cineon, blurs a parallel copy by a fixed amount, merges the paths with a difference, and grades the result with a low white point to amplify the residual.

Use it over plates or renders when matching grain, comparing noise between passes, or checking whether detail is texture or artifact. Values inside the group are fixed; there are no exposed amount or colorspace controls.

Script code

set cut_paste_input [stack 0]
version 12.1 v4
push $cut_paste_input
Group {
 name grainCheck
 tile_color 0x421010ff
 selected true
 xpos -1110
 ypos 410
 addUserKnob {20 User l template}
 addUserKnob {26 ""}
 addUserKnob {26 lbl l "" +STARTLINE T "Template v1.0"}
 addUserKnob {22 btn l DerekVFX.ca T "nuke.tcl('start', 'https://derekvfx.ca')" +STARTLINE}
}
 Input {
  inputs 0
  name Input
  xpos 447
  ypos 61
 }
 Dot {
  name Dot17
  note_font_size 40
  xpos 633
  ypos 251
 }
set Nda88c00 [stack 0]
 Colorspace {
  colorspace_out Cineon
  name Colorspace1
  label "value colorspace_in] -> \[value colorspace_out]"
  xpos 808
  ypos 253
 }
 Blur {
  channels rgba
  size 0.67
  name Blur1
  label "\[value size] px"
  xpos 808
  ypos 315
 }
push $Nda88c00
 Colorspace {
  colorspace_out Cineon
  name Colorspace3
  label "value colorspace_in] -> \[value colorspace_out]"
  xpos 682
  ypos 299
 }
 Merge2 {
  inputs 2
  operation difference
  bbox B
  name Merge4
  xpos 723
  ypos 433
 }
 Grade {
  whitepoint 0.0004
  name Grade1
  xpos 723
  ypos 459
 }
 Output {
  name Output1
  xpos 447
  ypos 1055
 }
end_group