PRMan Render Package

Package name: "prman"

The PRMan render package should be used when utilizing PhotoRealistic RenderMan renderers. The PRMan render package provides RIB generation for gops and gprims supported by PRMan renderers including automatic declaration of shader parameters. In addition, this render package facilitates generation of shadow maps. That feature is described separately in the Shadows section of this documentation.

Using the PRMan Render Package

The PRMan render package can be the "default" render package or it can be specified dynamically each time the render command is used. In both cases, the PRMan extension must be loaded.

Making PRMan the "Default" Render Package

If you want PRMan renderers to be used by default whenever the render command is issued, use set-render-package! (probably in your user initialization file).

       (set-render-package! "default" "prman")

Specifying PRMan Dynamically

The PRMan package can be specified when the render command is issued via the "package" parameter.

       (render 'package "prman" other options)

AL Support

Unsupported (ignored) gops/gprims

Extended gops and commands

render

The PRMan render package adds many options to the render command which are summarized in the Renderman Packages subsection of AL Language Reference section on rendering.

casts-shadows

The PRMan render package uses casts-shadows to control shadow map generation for individual objects. This feature is documented in the Shadows section.

Rendering Style Defaults

The default shell commands executed for "shaded" and "vector" styles are shown in the table below. The rendering style is specified using the "style" parameter. And the default shell command can be overridden using the "exec" parameter. (See renderman packages for information on these parameters to the render command.)

Default Shell Commands
style	command
"vector"	"render -vector ~s"
"shaded"	"render ~s"

Automatic Declaration of Shader Parameters

This feature automatically generates the "Declare" RIB requests for the non-standard shader parameters that you use in your AL program. For example, with the "prman" extension, the ri-declare call in the fragment below is unnecessary.

(world
   ...
   (ri-declare "basecolor" "uniform color")  <- not necessary!
   (surface "spatter" 'basecolor '#<1 0 0>)
   ...
   )

RIB Output Mode

When a typical image is rendered, the world model is evalued multiple times to create different RIB files for the scene, shadow maps, and motion blur. The function prman:rib-output-mode takes no arguments and returns a symbol, one of 'frame, 'shadow, or 'motion, which indicates the reason for the current evaluation of the world model.

Last updated: 1/28/97 / Steve May ( smay@cgrg.ohio-state.edu )

Any comments or suggestions appreciated.