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Foreground Compositing in Nuke

Foreground Compositing in Nuke

1. Background and Foreground Images.

Background : an actual scale, Foreground: 1:4 scale


2. Extract the green channel from the foreground.

Add Grade node : It is easier to extract the green channel.

Use a color picker to get values on the whitepoint and blackpoint on the grade node.

Press this icon and you can grab a color from whatever is in your viewer. Following are so helpful keys commends.

  • Command click in the viewer window to sample a pixel point within it.
  • Command + Option will sample the color from the image before the current operation. If you don’t do this it will sample live from the viewer windows ‘’post adjustment’’.
  • Shift combined with any combination of these key strokes will draw a marquee around a sample area.

Beware: When you have finished with the color picker press it again to disengage it or it will continue to sample.



 3.  Add KeyLight (I called this CoreKlight) node to extract the green channel. Get the screen color value and adjust the tuning.

Screen Shot 2013-11-07 at 10.08.32 PM



4. Extract the rest of the foreground besides the stair.

Screen Shot 2013-11-07 at 9.02.12 PM

Add Grade, Erode (fast) and blur. For the RotoPaint ->I added a blur node / value 3

Screen Shot 2013-11-07 at 9.10.33 PM

Screen Shot 2013-11-07 at 9.10.49 PM

Screen Shot 2013-11-07 at 9.10.57 PM

Screen Shot 2013-11-07 at 9.11.29 PM

Then connect this to the Edge KeyLight

Screen Shot 2013-11-07 at 9.19.55 PM

Screen Shot 2013-11-07 at 9.57.38 PM

Then add In node – The matte has been created.

Screen Shot 2013-11-07 at 10.17.26 PM

5. Add Key mix to finish.


Screen Shot 2013-11-07 at 10.00.07 PM