This channel outputs the orientation of every pixel surface in the image through representing the orientation of the Normal vector at this point.
This is useful for compositing purposes, i.e. when you need to select all the pixels facing downwards (i.e. to affect them with an aging adjustment), or all of them pointing upwards (i.e. to enhance their brightness).
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The render (left) and the Normals channel in Camera coordinates (right)
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