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Merge Log

ToolSets / Merge

Merge

2026-09-07

ToolSets/merge/mergeLog.nk

merge

log

logc

colorspace

utility

composite

View on GitHub

Merge two inputs in Alexa V3 LogC space, with optional bypass to a regular merge via the regular over control.

Merge Log takes A and B, unpremults A, converts both streams to Alexa V3 LogC, runs a Merge, then converts back out of LogC. The result is a composite performed in log rather than in the working space.

Use it when you need merge behaviour in LogC—for log plates, log-encoded elements, or any case where blending in linear is not what you want. Operation (output), also merge, and mix are exposed from the internal Merge.

Turn on regular over to skip the LogC round-trip and use a normal merge instead. Disable it to return to the log path.

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