The RenderMan 24 release of RenderMan XPU™ has been tailored to work within Look Development workflows.  It has an interactive renderer that is meant to be used by artists on their desktops as they shade and work with assets.  It is the perfect tool to use when shading.  RenderMan XPU has been integrated into Maya, Katana, Houdini, and Blender.

RenderMan XPU can be considered another variant of RenderMan itself – a companion to RenderMan RIS.  All of the techniques you have learned about to use RenderMan RIS apply to using XPU.  The BxDFs and the patterns all are usable with RenderMan XPU.  The look that you get from RenderMan XPU will be predictive of RenderMan RIS.  It won't be pixel-for-pixel accurate.  But it will give you a render that is very close to what you will get from RIS.  Take a look at the general documentation for the Shading BxDFs and Patterns to understand the possibilities you can achieve with RenderMan XPU and RIS.  While RenderMan XPU is predictive of RIS, take a look at the documentation for the differences between the two.  That documentation also covers what isn't yet supported in XPU.

Another point of sharing between RenderMan XPU and RenderMan RIS are textures.  RenderMan XPU uses the same textures as RenderMan RIS.  If you are manually creating textures with txmake, or if you are relying on the Texture Manager within the DCCs to automatically create the textures for you, you can use the same textures within both renderers.

RenderMan XPU is available to commercial customers of RenderMan.

While you can use RenderMan XPU on your farm, it has not been tailored to work in a farm context.  For example, it doesn't yet have adaptive sampling, which allows your render to terminate much earlier than it would otherwise.

RenderMan XPU will be constantly evolving with every major and minor release.  Use it within your look development workflows today.  Explore the boundaries of what it can do, and hopefully you can use it in other areas of your pipeline as well!