The Sampler Info texture is a color image that provides information about the scene, with the choice to show any of various aspects as color blocks. It provides information about various aspects of the shaded points such as position, normal, bump normal, reflection/refraction vectors and UVW coordinates, which previously were only available through the Extra Texture Render Element.

Sampler Info texture can be used either for world position passes or normal passes. It extracts particular information about the scene, converting the gathered information into RGB data for use in compositing.

Point Object Output

Output – Controls the output produced by the Sampler Info texture:

Default –
Point – Specifies the shading point in reference space.
Point Reference – Specifies the shading point in reference space.
Point Object – The X, Y, and Z coordinates of the point are converted to RGB data according to Object space. This outputs a Position Pass for use in compositing.
Point Camera – The X, Y, and Z coordinates of the point are converted to RGB data according to Camera space. This outputs a Position Pass for use in compositing.
Point Relative – X, Y, and Z coordinates in the object space of the Relative node are converted to RGB data. This outputs a Position Pass for use in compositing.
Gnormal – Specifies the geometric normal in world space.
Flipped Normal –
Normal – The direction of the normal at the particular shaded point according to which Coordinate system is set (Object, World, Camera or Relative space).
Normal Reference – Specifies the bump normal in relative space.
Normal Camera – The X, Y, and Z coordinates of the normals are converted to RGB data according to Camera space.
Normal Relative – This specifies the scene node relative to which the normal data is stored.
Bump Normal – Specifies the bump normal in world space.
Bump Normal Camera –  The X, Y, and Z coordinates of the normals are converted to RGB data according to Camera space.
Bump Normal Object – The X, Y, and Z coordinates of the normals are converted to RGB data according to Object space.
Bump Normal Relative – X, Y, and Z coordinates in the object space of the Relative node are converted to RGB data.
Reflection – Commonly used for adjusting reflections in the composite.
Reflection Object – The X, Y, and Z coordinates of the reflections are converted to RGB data according to Object space.
Reflection Camera – The X, Y, and Z coordinates of the reflections are converted to RGB data according to Camera space.
Reflection Relative – X, Y, and Z coordinates in the object space of the Relative node are converted to RGB data.
Refraction – Commonly used for adjusting refractions in the composite.
Refraction Object – The X, Y, and Z coordinates of the refractions are converted to RGB data according to Object space.
Refraction Camera – The X, Y, and Z coordinates of the refractions are converted to RGB data according to Camera space.
Refraction Relative –  X, Y, and Z coordinates in the object space of the Relative node are converted to RGB data.
View Dir – Specifies the view direction.
Frame Time –
Ray Time
Frame Index Offset – Outputs an offset from the current frame for motion blur intervals longer than one frame. For example, if you have a Motion Blur interval spanning three frames, the output will return -1, 0, or 1 depending on the ray time.
Facing Ratio
Ray Depth – Specifies the ray length.
Path Length – Specifies the path length. 
Transparency Level – Outputs how many transparency intersections have occurred at the point of intersecting the first surface along the ray path.
Camera near Clip Plane
Camera Far Clip Plane
Tangent UCamera
Tangent VCamera
Tangent UObject
Tangent VObject
Ray Direction
Pixel Center
Cam to World
Uv Coord
Uv Coord Clamp
Uv Coord Tile
Random by Render ID – Assigns a random color/texture by each object's render ID.
Random by Poly Shell – Assigns a random color/texture based on the polygon shell the current face belongs to. 
Random by Scene Name – Assigns a random color/texture by each object's full scene path.
Random by Instance ID – Assigns a random color/texture by each instance ID.
Material Id – Specifies the material ID if the surface supports it. 
Object Id – Specifies the object ID of the hit object.
Parent Object Id – Specifies the object ID of the parent object.
Velocity – Specifies the velocity at the intersection point in scene units per frame (in world space).
Speed – Specifies the speed at the intersection point in scene units per frame. 
Face Index – Correlates points between separate bakings of the same mesh.
Barycentric Coords – Displays the Barycentric coordinates of the rendered objects.

Uv Set Name – The default UVW mapping channel used when the Type is set to Uv coordinates. Specifies the UVW Channel to render by the name of the UV set. 

Uv Index –

Refraction Ior – Sets the index of refraction when Refraction vector is set as the Type.

Transform . Off –

Transform . V1 –

Transform . V2 –

Transform . V3 –