Dynamically crop to the current or an external bounding box in Nuke. This might save performance e.g. when piping in a roto shape bbox of a garbage matte.

CS_CropToBBox.tcl

set cut_paste_input [stack 0]
version 10.5 v7
push $cut_paste_input
Group {
 name CS_CropToBBox1
 tile_color 0xa57aaaff
 addUserKnob {20 CS_CropToBBox}
 addUserKnob {41 numpixels l "Add Pixels" T AdjBBox1.numpixels}
 addUserKnob {41 softness T Crop1.softness}
 addUserKnob {41 reformat T Crop1.reformat}
 addUserKnob {41 intersect -STARTLINE T Crop1.intersect}
 addUserKnob {41 crop l "black outside" -STARTLINE T Crop1.crop}
}
 Input {
  inputs 0
  name InputBBox
  xpos -920
  ypos 110
  number 1
 }
 Input {
  inputs 0
  name Input
  xpos -810
  ypos 110
 }
set Ne0913400 [stack 0]
 Switch {
  inputs 2
  which {{"\[expr \{\[exists parent.input1] ? true : false\}]"}}
  name Switch1
  xpos -920
  ypos 206
 }
push $Ne0913400
 CopyBBox {
  inputs 2
  name CopyBBox1
  xpos -810
  ypos 206
 }
 AdjBBox {
  numpixels 0
  name AdjBBox1
  xpos -810
  ypos 254
 }
 Crop {
  box {{bbox.x} {bbox.y} {bbox.r} {bbox.t}}
  name Crop1
  selected true
  xpos -810
  ypos 302
 }
 Output {
  name Output1
  xpos -810
  ypos 398
 }
end_group