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Merge Log

ToolSets / Merge

Merge

2026-09-07

ToolSets/merge/mergeLog.nk

merge

log

logc

colorspace

composite

utility

unpremult

View on GitHub

Merge A and B in Alexa V3 Log C space, with mix controls and a switch back to a regular non-log path.

Merge Log takes A and B, unpremultiplies A, converts both inputs to Alexa V3 Log C, merges them, then converts back out of Log C for the rest of the pipe.

Use it when the blend should happen in log space—typically against log plates or whenever a Log C merge is preferable to merging in the surrounding working space.

The group exposes the internal Merge output, also merge, and mix knobs. Enable regular over to bypass the log path and use the non-log merge instead.

Script code

set cut_paste_input [stack 0]
version 12.1 v4
push $cut_paste_input
push 0
Group {
 inputs 2
 name mergeLog
 tile_color 0x421010ff
 selected true
 xpos -1115
 ypos 517
 addUserKnob {20 User l mergeLog}
 addUserKnob {41 output T Merge1.output}
 addUserKnob {41 also_merge l "also merge" T Merge1.also_merge}
 addUserKnob {41 mix T Merge1.mix}
 addUserKnob {6 regularover l "regular over" -STARTLINE}
 addUserKnob {26 ""}
 addUserKnob {26 lbl l "" +STARTLINE T "Merge Log v1.0"}
 addUserKnob {22 btn l DerekVFX.ca T "nuke.tcl('start', 'https://derekvfx.ca')" +STARTLINE}
}
 Input {
  inputs 0
  name A
  xpos 142
  ypos 69
  number 1
 }
 Unpremult {
  name Unpremult1
  xpos 142
  ypos 116
 }
set Ndabec00 [stack 0]
 Input {
  inputs 0
  name B
  xpos 447
  ypos 61
 }
set Ndabe800 [stack 0]
 Merge2 {
  inputs 2
  operation matte
  bbox B
  name Merge1
  xpos 619
  ypos 325
 }
 set Cdabe400 [stack 0]
push $Ndabec00
 Colorspace {
  colorspace_out AlexaV3LogC
  name Colorspace1
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 142
  ypos 212
 }
 set Cdabe000 [stack 0]
push $Ndabe800
clone $Cdabe000 {
  xpos 447
  ypos 155
  selected false
 }
clone $Cdabe400 {
  inputs 2
  xpos 447
  ypos 312
  selected false
 }
 Colorspace {
  colorspace_in AlexaV3LogC
  name Colorspace2
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 447
  ypos 377
 }
 Switch {
  inputs 2
  which {{regularover}}
  name Switch1
  label "\[value which]"
  selected true
  xpos 447
  ypos 473
 }
 Output {
  name Output1
  xpos 447
  ypos 1055
 }
end_group