samplerInfo

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Sampler Info is a utility node you can use to get all kinds of information useful for building shader networks. The job of Sampler Info is to give you information about the each point on a surface as it is being "sampled", that is, calculated for rendering purposes.

Sampler Info can give you information about a point's position in space, its orientation and tangency, and its location relative to the camera.

Many of the attributes for this node provide values in "camera coordinate space". This is the local object space of the camera. Each camera (in its own space) is located at the point 0, 0, 0. It is looking straight along the negative Z axis, and the positive Y axis is pointing up.

In the table below, important attributes have their names listed in bold in the description column.

This node is MP safe

Related nodes

blendColors, clamp, lightInfo, gammaCorrect, surfaceLuminance, contrast, luminance, rgbToHsv, hsvToRgb, setRange, resolution, renderQuality, renderGlobals, renderGlobalsList, baseShadingSwitch, singleShadingSwitch, doubleShadingSwitch, tripleShadingSwitch

Attributes (37)

facingRatio, flippedNormal, matrixEyeToWorld, normalCamera, normalCameraX, normalCameraY, normalCameraZ, pixelCenter, pixelCenterX, pixelCenterY, pointCamera, pointCameraX, pointCameraY, pointCameraZ, pointObj, pointObjX, pointObjY, pointObjZ, pointWorld, pointWorldX, pointWorldY, pointWorldZ, rayDirection, rayDirectionX, rayDirectionY, rayDirectionZ, tangentUCamera, tangentUx, tangentUy, tangentUz, tangentVCamera, tangentVx, tangentVy, tangentVz, uCoord, uvCoord, vCoord

Long name (short name)	Type	Default	Flags
pointCamera (p)	float3	0.0, 0.0, 0.0
Point Camera gives you the position of the point being sampled, in camera coordinate space.
pointCameraX (px) float 0.0 The X component of Point Camera
pointCameraY (py) float 0.0 The Y component of Point Camera
pointCameraZ (pz) float 0.0 The Z component of Point Camera
pointObj (po)	float3	0.0, 0.0, 0.0
Point Obj gives you the position of the point being sampled, in the object's local coordinate space.
pointObjX (pox) float 0.0 The X component of Point Obj
pointObjY (poy) float 0.0 The Y component of Point Obj
pointObjZ (poz) float 0.0 The Z component of Point Obj
pointWorld (pw)	float3	0.0, 0.0, 0.0
Point World gives you the position of the point being sampled, in world coordinate space.
pointWorldX (pwx) float 0.0 The X component of Point World
pointWorldY (pwy) float 0.0 The Y component of Point World
pointWorldZ (pwz) float 0.0 The Z component of Point World
normalCamera (n)	float3	0.0, 0.0, 1.0
Normal Camera gives you the surface normal at the point being sampled, in camera coordinate space. The "surface normal" is a vector that points directly away from the surface (at right angles to it) at that point.
normalCameraX (nx) float 0.0 The X component of Normal Camera
normalCameraY (ny) float 0.0 The Y component of Normal Camera
normalCameraZ (nz) float 0.0 The Z component of Normal Camera
uvCoord (uv)	float2	0.0, 0.0
U V Coord gives you the U and V surface coordinates of the point being sampled.
uCoord (u) float 0.0 The u component of U V Coord
vCoord (v) float 0.0 The v component of U V Coord
rayDirection (r)	float3	0.0, 0.0, 1.0
Ray Direction gives you a vector that points from the point being sampled to the camera position, in camera coordinate space.
rayDirectionX (rx) float 0.0 The x component of Ray Direction
rayDirectionY (ry) float 0.0 The y component of Ray Direction
rayDirectionZ (rz) float 0.0 The z component of Ray Direction
tangentUCamera (tu)	float3	1.0, 0.0, 0.0
Tangent U Camera is the surface tangent in the U direction at the point being sampled, in camera coordinate space. Tangents are not well-defined for polygon objects.
tangentUx (tux) float 0.0 The X component of Tangent U Camera
tangentUy (tuy) float 0.0 The Y component of Tangent U Camera
tangentUz (tuz) float 0.0 The Z component of Tangent U Camera
tangentVCamera (tv)	float3	0.0, 1.0, 0.0
Tangent V Camera is the surface tangent in the V direction at the point being sampled, in camera coordinate space. Tangents are not well-defined for polygon objects.
tangentVx (tvx) float 0.0 The X component of Tangent V Camera
tangentVy (tvy) float 0.0 The Y component of Tangent V Camera
tangentVz (tvz) float 0.0 The Z component of Tangent V Camera
matrixEyeToWorld (e2w)	fltMatrix	identity
The transform to go from eye to world space
pixelCenter (pc)	float2	0.0, 0.0
Pixel Center gives you the location of the pixel in the final image that corresponds to the point being sampled. For example, let's say you are rendering an image at a resolution of 200 x 200. Then 0, 0 is the position of the lower-left corner of the image, and 200, 200 is the position of the upper-right corner. If we are sampling a point in the middle of the image, its Pixel Centre value would be approximately 100, 100.
pixelCenterX (pcx) float 0.0 The X component of Pixel Center
pixelCenterY (pcy) float 0.0 The Y component of Pixel Center
flippedNormal (fn)	bool	false
Flipped Normal tells you which side of a surface is being sampled. Most shaders treat both sides of a surface the same, but you may want to have them different. For example, if you were creating an image of money, you would want single flat surfaces with one image on one side, and a different image on the other side.
facingRatio (fr)	float	0.0
Facing Ratio gives you a number between 0 and 1 that tells you if the point being sampled is facing towards or away from the camera. A value of 1 means that it is facing the camera head-on. A value of 0 means that is is facing 90 degrees from the camera. In mathematical terms, Facing Ratio is the cosine of the angle between Ray Direction and Normal Camera.