This pass (also in combination with the Positions Pass) can be used with any 3D-capable composition program (e.g., The Foundry Nuke or eyeon Fusion) to create all sorts of effects such as re-illumination or re-shading without having to have the actual 3D geometry at hand.
The Normal Pass is an enhancement (with various modifiable parameters) to the Material Normal Multi-Pass function.
A Normal Pass encodes the direction of the visible surface normals as an RGB image.
Note that Photoshop CS5 often has difficulty with negative values and cannot correctly read the OpenEXR layers.
Make sure the following are enabled in the Render Settings menu when using this post effect:
Edge antialiasing is purposely not included in the Position Pass because this would make it unusable.