RfK Plugin Users Guide

RfK Plugin Users Guide

RenderMan for Katana builds upon the base of Katana's PRMan17 plugin, adding both features and improvements aimed toward an optimal RenderMan experience in Katana.

Getting Started with RfK starts from the basics of how to find and use PRMan-specific nodes and settings in RfK. This Users Guide extends that discussion with information about specific changes and features that are available within the RfK plugin package.

The current RfK plugin package offers support for:

  • Katana2.0v2
  • RenderMan ProServer 20.1

First Look

Once installed and configured, RfK looks much the same from within the Katana UI. PrmanGlobalSettings and PrmanObjectSettings nodes should be very familiar, however they have had several extensions and a few modifications.

Of particular note is the name modification of the parameters options.shadow.bias and options.rerender.lodrange.

Render Configuration

Out of the box RfK will default to Reyes rendering which is currently the PRMan default. In order to enable RIS rendering an integrator must be chosen and the hider needs to be set up for path tracing (using the "raytrace" hider with incremental mode turned on). The RfK RIS Introduction goes into more detail about configuring RfK for RIS rendering.

Where Are My Shaders?

RIS plugin shaders have no sloinfo equivalent, therefore we need to do a little extra work in order to distinguish these shaders from other ".so" files. For Katana 1.x RfK used a shaderManifest file to explicitly identify these plugin shaders. This process of shader discovery was drastically revamped for RfK 2.0. The shaderManifest has been deprecated and shaders are now identified using the presence of .args files. Specifics on setting this up can be found in the Shader Configuration documentation.

Plugin Customization

Katana 2.0 brings a new way of evaluating and affecting the scene as the scene graph is cooked using "Ops". RfK2.0 allows the user to add custom Ops to a configuration file as a way of customizing the plugin without needing to recompile the plugin. Please see the document Adding Custom Ops for information about creating and configuring custom Ops.

Lighting and Shading

RPS 20.0 ships with built-in production-quality shaders for use with RIS. For rendering in Reyes mode RfK also includes a set of general purpose RSL shaders.

When using RIS mode (i.e. when an integrator is active), only Bxdfs and Patterns can be used for surface shading. RSL surface shading will not work for RIS rendering. On the other hand, lighting continues to rely on the RSL Geometric Area Lights (e.g. RMSGeoAreaLight and RMSEnvLight) introduced in PRMan 18.

Displacement also continues to require RSL shaders. For convienence, a simple displacement shader - PxrDisplacement - has been included that can interface with RIS patterns. You can connect any of the Pattern nodes to this shader; it will use evalParam() to retrieve the appropriate values. All RSL shaders have had their parameters turned into inputs, but only shaders that have been authored to work with RIS patterns will evaluate the connection.

Note that opacity calculations still require traditional RSL as well.

For more information, see

OSL Shaders

OSL shaders in RfK 2.0 can be created and assigned like any other pattern shader in RIS. The conversion to PxrOSL happens under the hood inside the PRMan Katana plugin; the user never actually uses or sees a PxrOSL shader in the Katana node graph. Using OSL Shaders goes into more detail and discusses an example scene.

Live Rendering

RfK live rendering for RPS 20.0 demonstrates both extended capabilities and improved performance over previous versions of the plugin. In addition to the support for live updates of all available RIS features RfK also offers the following features:

  • Attributes and transform of geometric area lights can be edited.
  • The Object ID picker works during live rendering
  • Live updates of renderSettings (ROI, cropWindow)
  • Live updates of PrmanGlobalSettings (as supported by PRMan)

Beyond The Basics

Once you've got the basics down it's time to exploring some of the other features available in RfK and RPS 20.0. The following documents discuss how to use some of the more common features that are needed in a rendering pipeline:

The Example pages describe the example scenes contained in the RfK package. These scenes cover the above topics as well as shading examples, bokeh effect, and OSL shading.