XPU grows up
Pixar has pushed its hybrid CPU/GPU renderer, XPU, into full production status with the beta of RenderMan 27. XPU, introduced as experimental in earlier releases, now supports final-frame rendering. The engine adds interactive denoising for live look feedback, deep compositing outputs, and holdouts/mattes for layered workflows. Checkpointing allows partially saved renders, useful for iterative approval cycles. XPU also gains multi-GPU support, extending performance across several cards, and now runs OSL (Open Shading Language) filters. Limitations remain: no Cryptomatte support, no texture or light baking, no NURBS/quadrics rendering, and reduced performance with thousands of lights. macOS users must wait for a later dot release to run XPU at all.
RIS heads to retirement
RIS, RenderMan’s long-standing CPU-only engine, is still included but officially marked for deprecation. Pixar has not provided a removal version, but signals its intent to transition all users to XPU in the near future.
MaterialX integration
MaterialX, the open standard developed by ILM and adopted by the Academy Software Foundation, arrives in RenderMan 27. XPU can evaluate MaterialX shading graphs, allowing interchange between applications that support the format. This addresses a key demand for studio pipelines that rely on cross-software asset exchange.
Stylized Looks expand
The Stylized Looks framework, first introduced in RenderMan 24, expands with new non-photorealistic rendering options. Version 27 offers finer control over outlines, shading effects, and colour treatments, extending creative uses beyond feature film into stylised animation and design visualisation.
Pipeline features
RenderMan 27 continues Pixar’s effort to fit modern VFX pipelines. The update improves checkpointing and adds output flexibility for deep compositing passes. Support for mattes and holdouts makes it easier to combine live-action and CG layers, or to generate masks for postproduction.
Smaller additions
The release also improves interactive workflows with enhancements to the IPR (Interactive Preview Render). Users can now update shaders and geometry with fewer restarts, reducing iteration time. XPU’s viewport responsiveness has been tuned for lookdev, even on large assets. Another area of focus is light transport and filtering. XPU gains extended support for OSL filters, giving TDs more granular control over pixel output during rendering. This makes it possible to implement customised passes or in-house filtering logic without rewriting the core renderer.
Plugin updates
The release ships with updated plugins for Houdini, Katana, Maya, and Blender. Integration is designed to expose XPU features directly within host DCC applications, keeping lookdev and shot work inside familiar UIs.
Historical context
RenderMan has been Pixar’s in-house renderer since the late 1980s, originally built on the Reyes architecture optimised for micropolygon rendering. RIS, introduced in 2014, replaced Reyes with a path tracer better suited to global illumination. With version 27, Pixar signals the next phase: shifting from CPU-centric RIS to the hybrid CPU/GPU XPU engine, reflecting the industry-wide migration towards GPU acceleration. RenderMan 27 is available as a beta for registered users.
