Appendix B: Rendering attributes

NOTE:

The shading process uses the long names for attributes, so it doesn’t matter what you use for short names.

Output Attributes requested by Shading Groups

Name Long (short) Data Type Description

displacement (d)

float

Output surface displacement distance along the surface normal

outColor (oc)

outColorR (ocr)

outColorG (ocg)

outColorB (ocb)

float3

float

float

float

Output color

outGlowColor (ogc)

outGlowColorR (ogr)

outGlowColorG (ogg)

outGlowColorB (ogb)

float3

float

float

float

Output glow color

outMatteOpacity (omo)

outMatteOpacityR (omor)

outMatteOpacityG (omog)

outMatteOpacityB (omob)

float3

float

float

float

Output matte

outTransparency (ot)

outTransparencyR (otr)

outTransparencyG (otg)

outTransparencyB (otb)

float3

float

float

float

Output transparency

Rendering Attributes available per sample

Name Long (short) Data Type Description

farPointCamera (fc)

farPointCameraX (fcx)

farPointCameraY (fcy)

farPointCameraZ (fcz)

float3

float

float

float

used for volume, the far point of the visible interval in camera space

farPointObj (fo)

farPointObjX (fox)

farPointObjY (foy)

farPointObjZ (foz)

float3

float

float

float

used for volume, the far point of the visible interval in object space

farPointWorld (fw)

farPointWorldX (fwx)

farPointWorldY (fwy)

farPointWorldZ (fwz)

float3

float

float

float

used for volume, the far point of the visible interval in world space

filterSize (fs)

filterSizeX (fsx)

filterSizeY (fsy)

filterSizeZ (fsz)

float3

float

float

float

Filter size in (u, v, w) with which to filter textures

infoBits (ib)

32-bit unsigned integer

Passes information from one node that may be needed by another node.

Using this field, a file texture node with advanced filtering turned on (such as Quadratic filtering) can be used simultaneously as both a color map and a bump map. When rendering, Maya computes the color map using advanced filtering, but computes the bump map without it since advanced filtering is incompatible with bump mapping.

lightDataArray (ltd)

lightDirection (ld)

lightDirectionX (ldx)

lightDirectionY (ldy)

lightDirectionZ (ldz)

lightIntensity (li)

lightIntensityR (lir)

lightIntensityG (lig)

lightIntensityB (lib)

lightAmbient (la)

lightDiffuse (ldf)

lightSpecular (ls)

lightShadowFraction (lsf)

lightData

float3

float

float

float

float3

float

float

float

boolean

boolean

boolean

float

Multi-attribute representing all lights linked to the shading group

The light direction

The light intensity

Flag for ambient component

Flag for diffuse component

Flag for specular component

Percentage shadowing of the current light, provided shadows are enabled on the given light

matrixObjectToWorld (mow)

floatMatrix

Transformation from object space into world space

matrixWorldToObject (mwo)

floatMatrix

Transformation from world space into object space

mediumRefractiveIndex (mrfi)

float

refractive index of the medium through which the incident ray was travelling before it hit the point being shaded

normalCamera (n)

normalCameraX (nx)

normalCameraY (ny)

normalCameraZ (nz)

float3

float

float

float

Surface normal in camera space

numShadingSamples (ns)

char

Number of shading samples to take for this surface

objectId (oi)

int

unique ID for the object being shaded, may not be the same ID across frames

objectType (ot)

char

the rendering type (0=unknown, 1=surface, 2=volume(not particles), 3=blobby surface, 4=particle system, 5=image plane)

particleAge (pa)

float

age of the particle currently being shaded

particleColor (pc)

particleColorR (pcr)

particleColorG (pcg)

particleColorB (pcb)

float3

float

float

float

per-particle color as provided by a particle color mapper

particleId (pid)

int

unique identifier for the particle being shaded

particleIncandescence (pi)

particleIncandescenceR (pir)

particleIncandescenceG (pig)

particleIncandescenceB (pib)

float3

float

float

float

per-particle incandescence as provided by a particle incandescence mapper

particleLifespan (pls)

float

life-span of the current particle

particleTransparency (pt)

particleTransparencyR (ptr)

particleTransparencyG (ptg)

particleTransparencyB (ptb)

float3

float

float

float

per-particle transparency as provided by a particle transparency mapper

particleWeight (w)

float

weight of the current particle

pixelCenter (pc)

pixelCenterX (pcx)

pixelCenterY (pcy)

float2

float

float

center of the pixel currently being shaded in screen space

pointCamera (p)

pointCameraX (px)

pointCameraY (py)

pointCameraZ (pz)

float3

float

float

float

xyz location of geometry in camera space

pointObj (po)

pointObjX (pox)

pointObjY (poy)

pointObjZ (poz)

float3

float

float

float

xyz location of geometry in object space

pointWorld (pw)

pointWorldX (pwx)

pointWorldY (pwy)

pointWorldZ (pwz)

float3

float

float

float

xyz location of geometry in world space

rayDepth (rd)

int

during raytracing, the depth of the current ray (the primary ray has a depth of 0)

rayDirection (rad)

rayDirectionX (rdx)

rayDirectionY (rdy)

rayDirectionZ (rdz)

float3

float

float

float

The direction of the current intersection ray in camera space

rayOrigin (ro)

rayOriginX (rox)

rayOriginY (roy)

rayOriginZ (roz)

float3

float

float

float

The origin of the current intersection ray in camera space

refPointCamera (rpc)

refPointCameraX (rcx)

refPointCameraY (rcy)

refPointCamearZ (rcz)

float3

float

float

float

The current reference sample point that has to be shaded. Used in conjunction with reference objects.

refPointObject (rpo)

refPointObjectX (rox)

refPointObjectY (roy)

refPointObjectZ (roz)

float3

float

float

float

The current reference sample point that has to be shaded. Used in conjunction with reference objects.

refPointWorld (rpw)

refPointWorldX (rwx)

refPointWorldY (rwy)

refPointWorldZ (rwz)

float3

float

float

float

The current reference sample point that has to be shaded. Used in conjunction with reference objects.

tangentUCamera(tu)

tangentUx (tux)

tangentUy (tuy)

tangentUz (tuz)

float3

float

float

float

The U tangent of the surface in camera space

tangentVCamera (tv)

tangentVx (tvx)

tangentVy (tvy)

tangentVz (tvz)

float3

float

float

float

The V tangent of the surface in camera space

triangleNormalCamera (tnc)

triangleNormalCameraX (tnx)

triangleNormalCameraY (tny)

triangleNormalCameraZ (tnz)

float3

float

float

float

Normal of the visible triangle in camera space.

uvCoord (uv)

uCoord (u)

vCoord (v)

float2

float

float

texture UV coordinates in surface parametric space

uvFilterSize (uf)

uvFilterSizeX (ufx)

uvFilterSizeY (ufy)

float3

float

float

The sample (filter) size

vertexCameraOne (vc1)

vertexCameraOneX (c1x)

vertexCameraOneY (c1y)

vertexCameraOneZ (c1z)

float3

float

float

float

vertex one of the triangle currently being shaded in camera space

vertexCameraTwo (vc2)

vertexCameraTwoX (c2x)

vertexCameraTwoY (c2y)

vertexCameraTwoZ (c2z)

float3

float

float

float

vertex two of the triangle currently being shaded in camera space

vertexCameraThree (vc3)

vertexCameraThreeX (c3x)

vertexCameraThreeY (c3y)

vertexCameraThreeZ (c3z)

float3

float

float

float

vertex three of the triangle currently being shaded in camera space

vertexUvOne (vt1)

vertexUvOneU (t1u)

vertexUvOneV (t1v)

float2

float

float

texture coordinate of the triangle currently being shaded

vertexUvTwo (vt2)

vertexUvTwoU (t2u)

vertexUvTwoV (t2v)

float2

float

float

texture coordinate of the triangle currently being shaded

vertexUvThree (vt3)

vertexUvThreeU (t3u)

vertexUvThreeV (t3v)

float2

float

float

texture coordinate of the triangle currently being shaded

Rendering Attributes available per frame

Name Data Type Description

cameraFarClipPlane (fcp)

float

Far clipping plane distance for camera view

cameraNearClipPlane (ncp)

float

Near clipping plane for camera view

hFilmAperture (hfa)

float

width of the film (inches) from the camera being currently rendered

hFilmOffset (hfo)

float

horizontal offsets of the film (inches)

isPerspCamera (ipc)

boolean

If TRUE (non-zero), camera is perspective projection, else it is orthographic

lensSqueezeRatio (lsr)

float

squeeze ratio of the camera being currently rendered

matrixEyeToNormPersp (etp)

floatMatrix

Transformation from camera (eye) space to normalized perspective space

matrixEyeToWorld (e2w or etw)

floatMatrix

Transformation from camera (eye) space to world space

matrixNormPerspToEye (pte)

floatMatrix

Transformation from normalized perspective space to camera (eye) space

matrixWorldToEye (wte)

floatMatrix

Transformation from world space to camera (eye) space

vFilmAperture (vfa)

float

height of the film (inches) from the camera being currently rendered

vFilmOffset (vfo)

float

vertical offsets of the film (inches)

xHighRenderRegion (hrx)

int

resolution of the image in x

yHighRenderRegion (hry)

int

resolution of the image in y

xLowRenderRegion (lrx)

int

always 0

yLowRenderRegion (lry)

int

always 0

xPixelAngle (xpa)

float

The maximum angle subtended in X or Y by a single pixel