The Shuffle node is like a stripped-down version of the ShuffleCopy and is 'read' in the same way. The main difference between them is that the Shuffle node will not accept a second feed. It can:
- Replace a channel with black or white.
- Move a channel from one place to another.
- This is, for example, useful for moving the green channel from an image into the alpha (green channels are a good place to start when making a luminance key).
- It is also useful for converting a single-channel image, such as a grey-scale image, into an RGB image (Nuke reads the information from grey-scale images into the red channel and fills the green and blue channels as black).
- A significant use is to move the render layers from a 3D render (such as ambient occlusion, reflection and motion) into the RGB channels where they can be worked on more easily.
- Create brand new channels from nothing.
- Remove channels altogether.