RenderMan Artist Tools

PhotoRealistic RenderMan
Application Note #9


PhotoRealistic RenderMan Options And Attributes

May, 1990

This application note outlines in tabular form all the options and attributes available with PhotoRealistic RenderMan. "Options" refer to choices available within the graphics state. All options must be set prior to rendering a frame. Options are grouped by these categories:

"Attributes" are parameters in the graphics state that may change while geometric primitives are being defined. Attributes are grouped by these categories:

In the following pages, a RIB example using non-default values precedes each set of option descriptions. The descriptions themselves are very brief. Complete descriptions of all options and attributes can be found in the following publications:

Asterisks in the “Default” column denote values whose defaults depend on values set in other routines.

RenderMan Options

DISPLAY OPTIONS

OptionType DefaultDescription
Display "RenderPicture" "framebuffer" "rgb"Spec ; Book p. 155
name string"ri.pic" Determines whether to display to framebuffer or file.
type token "tiff" *Name of display device or file
mode token "rgba"Image output type
Format 640 320 1 Spec ; Book p. 156
xres int512 *output image x resolution
yres int384 *output image y resolution
pixelaspectratio float1.0 *ratio of width to height of a single pixel
CropWindow [.3 .5 .6 .9] Spec ; Book p. 162
xmin float0Left edge of partial image
xmax float1Right edge of partial image
ymin float 0Top edge of partial image
ymax float1Bottom edge of partial image
FrameAspectRatio 2.0Spec ; Book p. 15
frameaspectratio float4/3 *Width/height ratio of the output image
Imager "background" Spec; Book p. 181
nameshader"null"A procedure defining an image or pixel operator. (partially implemented--See 4.1.1 in User Manual
ScreenWindow [-2.0 2.0 -1 1] Spec ; Book p. 150
left float -4/3 *Left screen coordinate of the area to be rendered
right float 4/3 * Right screen coordinate of the area to be rendered
bottom float-1 * Bottom screen coordinate of the area to be rendered
top float1 * Top screen coordinate of the area to be rendered

CAMERA TRANSFORMATIONS

OptionType DefaultDescription
Projection "orthographic"Spec ; Book p. 149
nametoken "orthographic"The camera to screen projection.
Clipping .1 10000 Spec; Book p. 145
nearfloat (epsilon)Position of the near clipping plane.
farfloat (infinity)Position of the far clipping plane.
DepthOfField 22 45 1200Spec; Book p. 185
fstopfloat (infinity)Determines the aperture size of the "digital" camera.
focallength float-Distance between the focal point and the image plane.
focaldistancefloat-Distance at which objects appear in focus.
Shutter [0.1 0.9]Spec; Book p. 190
minfloat0The time when the virtual shutter opens.
maxfloat0The time when the virtual shutter closes.

ANTIALIASING OPTIONS

OptionType DefaultDescription
PixelVariance 0.01Spec; Book p. 179
variationfloat(turned off)Variance of computed from true pixel value.
PixelSamples 4 2Spec; Book p. 176
xsamplesfloat2Supersampling rate in the horizontal direction.
ysamplesfloat2Supersampling rate in the vertical direction.
PixelFilter "triangle" 3 3Spec; Book p. 176
filterfuncfunctiongaussianType of filter.
xwidthfloats2The horizontal width of the filter.
ywidthfloats2The vertical width of the filter.

QUANTIZATION

OptionType DefaultDescription
Exposure 2.3 1.0 Spec; Book p. 180
gainfloat 1.0Gain of the exposure process.
gammafloat1.0Gamma of the exposure process.
Quantize "rgba" 255 0 255 0.5Spec; Book p. 183
oneinteger 255Integer pixel value of white.
minimuminteger0Minimum legal pixel value.
maximuminteger255Maximum legal pixel value.
ditheramplitudefloat0.5Random dithering amplitude.
Quantize "z" 32767 0 32767 0Spec; Book p. 183
oneinteger 0Integer depth value of far-plane distance.
minimuminteger-Minimum legal depth value.
maximuminteger-Maximum legal depth value.
ditheramplitudefloat-Random dithering amplitude.

MISCELLANEOUS OPTIONS

OptionType DefaultDescription
Hider "hidden"Spec; Book p. 54
typetoken"hidden"Type of hidden surface algorithm performed.

PhotoRealistic RenderMan-SPECIFIC OPTIONS

ParameterType DefaultDescription
Option "limits" "bucketsize" [4 4] Manual p. 10
bucketsize 2 integers16, 16Dimensions of pixel blocks the screen gets divided into for resolving visible surface calculations.
Option "limits" "gridsize" [128]Manual p. 10
gridsizeinteger256The maximum number of micropolygons shaded at once.
Option "limits" "texturememory" [2048] Manual p. 11
texturememoryinteger256Maximum size (in Kbytes) of the texture data cache.
Option "limits" "eyesplits" 10Manual p. 11
eyesplitsinteger10The failure detection threshold which determines the maximum number of eye-plane splits.
Option "shadow" "bias0" 0.45 "bias1" 1.0Manual p. 12
bias0float0.15Bias guards against the problem of surface self-shadowing.
Option "searchpath" [".:/usr/lcl/prman/lib/shaders"]Manual p. 12
shaderstring".:/usr/local/prman/prman/lib/shaders"
A search path definition for shader files. (The syntax for the path depends on the operating system. UNIX is used here only by way of example.)
Option "searchpath" ["texdir"]Manual p. 12
texture string"."A search path definition for texture files.
Option "rib" "format" "binary" Manual p. 12
formattoken"ascii"RIB file output format (ascii or binary).

Note: There are two options that can be enabled through the parameter list of the Display command and one option that can be enabled through the parameter list of the Hider command:

ParameterType DefaultDescription
Display \xbc "merge" [1] "origin" [512 0]Manual p. 12
mergeboolean0Allows framebuffers to be configured to merge the generated image over an existing image.
origin2 integers0, 0Set origin of output window on a frame buffer device.
Hider \xbc "jitter" [0]Manual p. 11
jitterboolean1The default hider, "hidden", has one parameter option which enables/disables stochastic sampling, jitter.

RenderMan ATTRIBUTES

SHADING ATTRIBUTES

Attribute TypeDefaultDescription
Color [.3 .9 .1] Spec; Book p. 213
color colorcolor (1, 1, 1) The reflective color of the object.
Opacity [.7 0 0] Spec; Book p. 213
color colorcolor (1, 1, 1) The opacity of the object.
TextureCoordinates [.1 .9 .9 .1 .1 .9 .9 .9] Spec; Book p. 251
s1,t1 2 floats(0, 0)Upper left parametric primitive texture coordinate.
s2,t2 2 floats(1, 0)Upper right parametric primitive texture coordinate.
s3,t3 2 floats(0, 1)Lower left parametric primitive texture coordinate.
s4,t4 2 floats(1, 1) Lower right parametric primitive texture coordinate.
LightSource "spotlight" 2 "coneangle" 5Spec; Book p. 216
Light Sources shader list "null"Add to the list of active light source shaders.
Surface "wood" "roughness" 0.3 "grain" 8Spec; Book p. 231
Surface shader"defaultsurface"A shader controlling the surface shading model.
Atmosphere "fog"Spec; Book p. 235
Atmosphere shader"null"A volume shader that specifies how the color of light changes as it travels from a visible surface to the eye.
ShadingRate 0.25Spec; Book p. 214
size float0.25Maximum distance between shading samples on a surface.
ShadingInterpolation "smooth"Spec; Book p. 215
type token"constant"How the results of shading are interpolated across a polygon.
Matte 1Spec; Book p. 216
onoff boolean0Make surfaces opaque to the rendering program, but transparent to the output.

GEOMETRIC ATTRIBUTES

AttributeTypeDefaultDescription
GeometricApproximation "flatness" 2.5Spec; Book p. 172
flatness float (turned off) The largest deviation of an approximation of a surface from the true surface in raster coordinates.
Orientation "rh" Spec; Book p. 121
orientation token"outside"Define primitives in left- or right-handed coordinate system.
Sides 1Spec1; Book p. 119
sides integer2Whether surfaces are to be backface culled.
Displacement "bumpy"Spec; Book p. 260
Displacement shader"null"Displacement shader specifying small changes in surface geometry.
Basis "bezier" 1 [-1 3 -3 1 3 -6 3 0 -3 3 0 0 1 0 0 0] 1 Spec ;Book p. 93
ubasis, vbasis2 matricesBezier, BezierBasis matrices for bicubic patches.
ustep, vstep2 integers3,3
TrimCurve SpecBook p. 249
ncurves A list of trim curves which bound NURBS.
order
knot
min
max
n
u
v
w

PHOTOREALISTIC RENDERMAN-SPECIFIC ATTRIBUTES

ParameterTypeDefaultDescription
Attribute "dice" "binary" [1]Spec; Book p. 183
binary boolean0Whether lowest level patches get diced into a grid of micropolygons with power-of-two dimensions.
Attribute "displacementbound" "sphere" [1.3] "coordinatesystem" ["shader"]
Spec; Book p. 183
sphere float0.0coordinatesystem string "object" Increases the sizes of calculated bounding boxes to account for effects of displacement mapping.
Attribute "identifier" "name" "ball" Spec ; Book p. 183
namestringNULLAssign a name to an individual primitive.

The following calls are not implemented by PhotoRealistic RenderMan.

ParameterTypeDefaultDescription
ColorSamples 1 [.333 .333 .333] [1.0 1.0 1.0] Spec; Book p. 43
n integer3 Number of color components in colors.
fromRGB array(identity) Matrix conversion from RGB to color.
toRGB array(identity)Matrix conversion to RGB from color.
RelativeDetail 3.0 Spec; Book p. 196
relativedetail float 1.0A multiplicative factor used to change level of detail.
AreaLightSource "ambient" 2 "intensity" 1 Spec; Book p. 225
Area Light Sources shader"null"The area light source that is being defined.
Interior "water" Spec; Book p. 235
Interior Volume shader"null"A volume shader that specifies how the color of light is changed as it traverses a volume in space.
Exterior "fog" Spec; Book p. 235
Exterior Volume shader"null"A volume shader that specifies how the color of light is changed as it traverses a volume in space.
Bound [0 0.5 0 0.5 0.9 1] Spec; Book p. 125
xmin float(infinite)Coordinate for left side of bounding box.
xmax float(infinite)Coordinate for right side of bounding box.
ymin float(infinite)Coordinate for bottom of bounding box.
ymax float(infinite)Coordinate for top of bounding box.
zmin float (infinite)Coordinate for front of bounding box.
zmax float(infinite)Coordinate for back of bounding box.
DetailRange [0 0 10 20] Spec; Book p. 197
minvisible float0Current range of detail. If the current detail is in this range, geometric primitives are rendered.
lowertransition float0
uppertransition float infinity
maxvisible float infinity
 

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