Options & Attributes
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:
- Display Options
- Camera Transformations
- Antialiasing Options
- Quantization
- Miscellaneous Options
- PhotoRealistic RenderMan-specific Options
"Attributes" are parameters in the graphics state that may change while geometric primitives are being defined. Attributes are grouped by these categories:
- Shading Attributes
- Geometric Attributes
- PhotoRealistic RenderMan-specific Attributes
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:
- "The RenderMan Interface," version 3.1 (September, 1989), referred to as Spec
- "The RenderMan Companion: A Programmer's Guide to Realistic Computer Graphics," by Steve Upstill (Addison-Wesley, 1989), referred to as Book
- PhotoRealistic RenderMan 3.0 User's Manual in "PhotoRealistic RenderMan Development Software for Realistic Computer Graphics" documentation (September, 1989), referred to as Manual.
Asterisks in the “Default” column denote values whose defaults depend on values set in other routines.
DISPLAY OPTIONS
| Option | Type | Default | Description |
|---|---|---|---|
| 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 | int | 512 * | output image x resolution |
| yres | int | 384 * | output image y resolution |
| pixelaspectratio | float | 1.0 * | ratio of width to height of a single pixel |
| CropWindow [.3 .5 .6 .9] | Spec ; Book p. 162 | ||
| xmin | float | 0 | Left edge of partial image |
| xmax | float | 1 | Right edge of partial image |
| ymin | float | 0 | Top edge of partial image |
| ymax | float | 1 | Bottom edge of partial image |
| FrameAspectRatio 2.0 | Spec ; Book p. 15 | ||
| frameaspectratio | float | 4/3 * | Width/height ratio of the output image |
| Imager "background" | Spec; Book p. 181 | ||
| name | shader | "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 | float | 1 * | Top screen coordinate of the area to be rendered |
CAMERA TRANSFORMATIONS
| Option | Type | Default | Description |
|---|---|---|---|
| Projection "orthographic" | Spec ; Book p. 149 | ||
| name | token | "orthographic" | The camera to screen projection. |
| Clipping .1 10000 | Spec; Book p. 145 | ||
| near | float | (epsilon) | Position of the near clipping plane. |
| far | float | (infinity) | Position of the far clipping plane. |
| DepthOfField 22 45 1200 | Spec; Book p. 185 | ||
| fstop | float | (infinity) | Determines the aperture size of the "digital" camera. |
| focallength | float | - | Distance between the focal point and the image plane. |
| focaldistance | float | - | Distance at which objects appear in focus. |
| Shutter [0.1 0.9] | Spec; Book p. 190 | ||
| min | float | 0 | The time when the virtual shutter opens. |
| max | float | 0 | The time when the virtual shutter closes. |
ANTIALIASING OPTIONS
| Option | Type | Default | Description |
|---|---|---|---|
| PixelVariance 0.01 | Spec; Book p. 179 | ||
| variation | float | (turned off) | Variance of computed from true pixel value. |
| PixelSamples 4 2 | Spec; Book p. 176 | ||
| xsamples | float | 2 | Supersampling rate in the horizontal direction. |
| ysamples | float | 2 | Supersampling rate in the vertical direction. |
| PixelFilter "triangle" 3 3 | Spec; Book p. 176 | ||
| filterfunc | function | gaussian | Type of filter. |
| xwidth | floats | 2 | The horizontal width of the filter. |
| ywidth | floats | 2 | The vertical width of the filter. |
QUANTIZATION
| Option | Type | Default | Description |
|---|---|---|---|
| Exposure 2.3 1.0 | Spec; Book p. 180 | ||
| gain | float | 1.0 | Gain of the exposure process. |
| gamma | float | 1.0 | Gamma of the exposure process. |
| Quantize "rgba" 255 0 255 0.5 | Spec; Book p. 183 | ||
| one | integer | 255 | Integer pixel value of white. |
| minimum | integer | 0 | Minimum legal pixel value. |
| maximum | integer | 255 | Maximum legal pixel value. |
| ditheramplitude | float | 0.5 | Random dithering amplitude. |
| Quantize "z" 32767 0 32767 0 | Spec; Book p. 183 | ||
| one | integer | 0 | Integer depth value of far-plane distance. |
| minimum | integer | - | Minimum legal depth value. |
| maximum | integer | - | Maximum legal depth value. |
| ditheramplitude | float | - | Random dithering amplitude. |
MISCELLANEOUS OPTIONS
| Option | Type | Default | Description |
|---|---|---|---|
| Hider "hidden" | Spec; Book p. 54 | ||
| type | token | "hidden" | Type of hidden surface algorithm performed. |
PhotoRealistic RenderMan-SPECIFIC OPTIONS
| Parameter | Type | Default | Description |
|---|---|---|---|
| Option "limits" "bucketsize" [4 4] | Manual p. 10 | ||
| bucketsize | 2 integers | 16, 16 | Dimensions of pixel blocks the screen gets divided into for resolving visible surface calculations. |
| Option "limits" "gridsize" [128] | Manual p. 10 | ||
| gridsize | integer | 256 | The maximum number of micropolygons shaded at once. |
| Option "limits" "texturememory" [2048] | Manual p. 11 | ||
| texturememory | integer | 256 | Maximum size (in Kbytes) of the texture data cache. |
| Option "limits" "eyesplits" 10 | Manual p. 11 | ||
| eyesplits | integer | 10 | The failure detection threshold which determines the maximum number of eye-plane splits. |
| Option "shadow" "bias0" 0.45 "bias1" 1.0 | Manual p. 12 | ||
| bias0 | float | 0.15 | Bias guards against the problem of surface self-shadowing. |
| Option "searchpath" [".:/usr/lcl/prman/lib/shaders"] | Manual p. 12 | ||
| shader | string | ".:/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 | ||
| format | token | "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:
| Parameter | Type | Default | Description |
|---|---|---|---|
| Display \xbc "merge" [1] "origin" [512 0] | Manual p. 12 | ||
| merge | boolean | 0 | Allows framebuffers to be configured to merge the generated image over an existing image. |
| origin | 2 integers | 0, 0 | Set origin of output window on a frame buffer device. |
| Hider \xbc "jitter" [0] | Manual p. 11 | ||
| jitter | boolean | 1 | The default hider, "hidden", has one parameter option which enables/disables stochastic sampling, jitter. |
RenderMan ATTRIBUTES
SHADING ATTRIBUTES
| Attribute | Type | Default | Description |
|---|---|---|---|
| Color [.3 .9 .1] | Spec; Book p. 213 | ||
| color | color | color (1, 1, 1) | The reflective color of the object. |
| Opacity [.7 0 0] | Spec; Book p. 213 | ||
| color | color | color (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" 5 | Spec; Book p. 216 | ||
| Light Sources | shader list | "null" | Add to the list of active light source shaders. |
| Surface "wood" "roughness" 0.3 "grain" 8 | Spec; 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 0.25 | Spec; Book p. 214 | ||
| size | float | 0.25 | Maximum 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 1 | Spec; Book p. 216 | ||
| onoff | boolean | 0 | Make surfaces opaque to the rendering program, but transparent to the output. |
GEOMETRIC ATTRIBUTES
| Attribute | Type | Default | Description |
|---|---|---|---|
| GeometricApproximation "flatness" 2.5 | Spec; 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 1 | Spec1; Book p. 119 | ||
| sides | integer | 2 | Whether 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, vbasis | 2 matrices | Bezier, Bezier | Basis matrices for bicubic patches. |
| ustep, vstep | 2 integers | 3,3 | |
| 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
| Parameter | Type | Default | Description |
|---|---|---|---|
| Attribute "dice" "binary" [1] | Spec; Book p. 183 | ||
| binary | boolean | 0 | Whether 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 | float | 0.0 | coordinatesystem string "object" Increases the sizes of calculated bounding boxes to account for effects of displacement mapping. |
| Attribute "identifier" "name" "ball" | Spec ; Book p. 183 | ||
| name | string | NULL | Assign a name to an individual primitive. |
The following calls are not implemented by PhotoRealistic RenderMan.
| Parameter | Type | Default | Description |
|---|---|---|---|
| ColorSamples 1 [.333 .333 .333] [1.0 1.0 1.0] | Spec; Book p. 43 | ||
| n | integer | 3 | 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 | 1.0 | A 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 | float | 0 | Current range of detail. If the current detail is in this range, geometric primitives are rendered. |
| lowertransition | float | 0 | |
| uppertransition | float | infinity | |
| maxvisible | float | infinity | |