One of the most valuable features of RenderMan for Katana (RfK) is the ability to create and manage Lights. The sections below provide a brief overview of how to take advantage of these capabilities.
Using Light Filters
Light filters are a powerful way to control a light's appearance. With Katana 2.0 or 2.1, light filters can be added to a scene with a PrmanLightFilterCreate node. GafferThree support for light filters is available in Katana 2.2 and above. You can find a detailed explanation about light filter setup in the link below:
Using Portal Lights
PxrPortalLight is an optimized environment light. Because Portals are lights, not light filters, they require a special workflow. GafferThree support for portal lights is coming in a future version of Katana. You can find a detailed explanation about portal light setup in the link below:
Light Sampling capabilities are available through sample balancing in the integrator, typically with the numLightSamples option. The Light Sampling page provides more detail about how light sampling is managed in RenderMan.