Elemental © Disney/Pixar

Welcome to RenderMan 25.0

RenderMan version 25 provides major upgrades to look development and batch rendering, with many tools that improve artist workflows and complement the creative process. Here are some of the highlights:

Major Features in RenderMan 25.0

RIS

• Innovative Denoising Technology — The RenderMan Denoiser is a completely new state-of-the-art denoising technology developed by Disney Research, which takes a new approach to denoising, using machine learning and training data from Disney, ILM, and Pixar. The Denoiser can significantly reduce render times for both feature animation and VFX, while delivering images of the highest quality. This denoiser replaces the current offline denoiser in RenderMan that was developed at WDAS.
  
  The new Denoiser excels on complex, detailed imagery that would cause other denoisers to fail. This technology has been used in production for several years now, including every Pixar feature animation since Toy Story 4 and has dramatically reduced render times at ILM, Pixar, and WDAS.
  
  

• Stylized Looks – RenderMan’s toolset for generating nonphotorealistic images receives various updates, including numerous enhancements to give artists more control over Toon shading, Illustrative lighting through hatching & watercolor, and Linework. Some of the highlights include an overhauled Toon shading system with more creative controls, Illustrative lighting with more texture presets for hatching & watercolor, optimized Linework, blending of physically based shading with a stylized look, and new Preset Browser Stylized Looks materials that extends the library.
  
  

• MaterialX Lama – We’re bringing the latest improvements from ILM.  They have enhanced the approximation of the physical interaction of light between different material layers, giving artists more physically accurate results.  ILM has also added a new iridescence material response that has been added to RenderMan 25.
  
  

• Baking performance and control – If you’re using RenderMan to bake global illumination into textures for real-time applications, we’ve improved performance up to 2x, as well as added additional controls for controlling resolution.

XPU

• Volumes — The introduction of volume aggregates in XPU is a major achievement, allowing for faster iteration times during the look development phase, as well as quicker final renders. Now render pyrotechnics and more with XPU!
  
  
• XPU Lookdev improvements – Full support for LPEs and arbitrary AOVs, as well as support for thin glass and related optimizations (VIRP).  Also included is support for trace subsets, including support for subsurface subsets in PxrSurface. Curvature and roughness mollification is now supported. These features make XPU renders an even closer match to RIS in a wider variety of look development scenarios.
  
  
• Deformation motion blur - XPU now supports deformation motion blur of all geometric primitives. Together with transformation motion blur and camera motion blur, you can use XPU for quality control renders to validate animation caches.
  
  
• XPU rendering controls – Includes the ability to enable and disable caustics, as well as controls over the trace depth for diffuse and specular rays, not only globally and interactively, but on a per-object basis. Russian Roulette is also now supported. These give finer grained control over convergence speed and help you better match XPU renders to RIS.
  
  
• Enhanced camera functionality – Additional camera features have been added to XPU to better match the options in RIS, giving users the ability to interactively dial in depth of field, vignetting, and other camera effects.
  
  
• Interactivity — Interactivity is a key feature of XPU in RenderMan 25, which prioritizes interactive performance by improving the responsiveness of XPU to camera movements and shader parameter changes, through features such as Progressive Pixels, allowing artists to make quicker and more informed decisions while providing faster image feedback for refining their choices.
  
  
• Texturing improvements – The texture cache has been improved to perform better on GPUs that are memory constrained.  You will get faster renders from the GPU if the texture cache needs to do out-of-core texture lookups. In addition, several issues surrounding the invalidation of textures have been addressed, and the default texture filter width for XPU now matches RIS exactly.

For further details about RenderMan XPU™, see the following documentation sections:

• XPU Guide - Overview of XPU in RenderMan 25.
  
• Shader & Look Development with XPU - Details on lookdev with XPU.
• Features & Limitations - Understand the differences between XPU and RIS and known limitations.
  
  
  

Additional Features

RenderMan version 25 also includes:

• VFX Reference Platform 2021  — All plug-ins are now updated to conform to the standard. 
  
  
• MaterialX & Solaris  — Ongoing collaboration with the USD team has yielded positive results for material exchange with direct support for MaterialX in Solaris, and with support to follow for MaterialX in many other DCCs. RenderMan is committed to delivering the best-in-class material exchange experience for our users and is working closely with the USD team to make this progress possible.

Stylized Looks Details

• PxrStylizedControl:

• Toon Mask support

• NPRdistort feature & AOV requirement

• New parameters for Distort feature: distortU, distortV, distortBumpSwitch, distortScale

• Toon_Mask switch & feature

• PxrStylizedToon:

• Color Spline Ramp for added creativity
• Toon Mask support (with PxrStylizedControl)
• UI updates
• Improved whiteshader calculations
• Signal Pre Gain/Gamma
• Threshold Min and Max for Signal Energy

• PxrStylizedHatching:

• Triplanar Projections: 8-val progressive blending
• Triplanar Projections: new UI dropdown behavior with default sticky projection
• Toon Shading in Hatching: 1 button replace textures
• Hatching Mask non binary: works with upstream Pxr nodes (ex PxrRamp)
• Updated blending with Black Darkest & White Lightest
• Rainbow test visualizer: updated blending
• Signal Pre Gain/Gamma

• New Override_SignalAOV_CameraRange toggle

• Rename Diffuse Luminance to Signal Luminance

• Conditional visibility on Signal Energy From the dropdown, based off Camera Range (since its ignored when on)

• Re-arranged order of Camera Range page controls to under Signal AOV

• New UI page for Color, Masking, Output

• Extended help for Texture Sets

• Rework of Camera Range Hatching functionality: works as a separate mode with other Visualizer modes, not a separate Visualizer only option

• Camera Range Hatching works with Signal Pre Gain/Gamma & Spline

• Fix Visualizer Hatching Blend to not be always red

• Fix Hatching Mix to work with Visualizer mode "Hatching on Beauty"

• New hatching_aov_channel drop-down choice for RGB

• Support daisy chain of custom AOV & RGB channel for each Hatching node

• Visualizer Hatching On Beauty (instead of Hatching Final)

• New hatching_aov_string custom user AOV per node if daisy chained

• New Toon_Colors_Switch functionality for Toon Shading overrides textures

• PxrStylizedLines:

• • Algorithm optimization for Line Thickness & Dilate+Sort, speed improvements

  • New Distort Lines feature

    • Works with PxrStylizedControl Distort data

    • New NPRdistort AOV requirement
      
      
      
      

Look Differences

All the look differences below are in RIS.  In XPU, we continue to make fixes to make it a closer match to RIS.

• The roughness parameter in LamaHairChiang has been reparameterized to produce a more linear response.
• The default longitudinal roughness values in LamaHairChiang have changed from 0.2 0.3 0.3 to 0.13 0.27 0.27.  (The azimuthal roughness is unchanged at 0.35).

Deprecations

We have deprecated the C++ out-of-the-box patterns in favor of an equivalent set of OSL patterns.  The new patterns have the same names and functionality as the old patterns, so no changes to your networks are necessary.  We now provide OSL patterns because they run in both XPU and RIS, whereas the C++ patterns only worked with RIS.

Known Limitations

Installation + Licensing

• macOS 11 or 12 (Big Sur or Monterey): The installer can download the packages from Pixar, but can't run them to get them unpacked.  You must manually double-click on the .pkg files that the installer leaves in the Downloads folder.
• macOS 11 or 12 (Big Sur or Monterey): The License Server can fail.  Restarting it should make it work again.

Denoiser

• macOS/Apple Silicon: The denoiser is not supported on Apple Silicon, even with Rosetta.

RIS and XPU

• Color Management: Although we have upgraded to the VFX Reference Platform 2021, there are still color management limitations:
  • IT does not support OCIO 2.0 configs yet.

RIS

• Some parameters in the set of the MaterialX Lama nodes have changed their name. Specifically, the "color" and "normal" names have been renamed to avoid conflict with some OSL keywords. The parameter "newParamNames" has been added to the MaterialX Lama nodes to be able to swap between the old and the new parameter names. This will allow users the ability of using lama networks created with the old param set and still properly rendered in 25. In 26, only the new parameter names will be supported and the newParamNames parameter will disappear.

Known Limitations - Existing

Interactive/Live Rendering Limitations

• Bucket order or size cannot be changed during live rendering.
• Changes to Presence do not update when using the opacity cache option (RIS only).
• Objects are not re-diced during interactive camera edits.
• Mesh lights cannot be interchanged as geometry without restarting.

RenderMan Pro Server

• Shading
  
  • PxrUnified integrator is currently experimental as it does not yet support all the standard rendering features.
  • <primstr:nameofvalue> substitution of data from a constant primvar or user attribute on an object for dynamic filename substitution is not yet working for the gettextureinfo() OSL call.
  • Using the ' . ' character in the handle for an OSL shader could cause unpredictable results during re-rendering.
• General rendering
  • Load on demand procedurals are not supported anymore, all procedurals are now loaded immediately.
  • We do not read point data from OpenVDB files.
  • Per-Instance baking is not supported, only the reference instance.
  • 3d baking: no direct bake-to-ptex support.
  • PxrBakePointCloud cannot directly render ptex.
  • Sample/Display filter plug-ins do not have access to lighting services for light dependent effects, e.g. lens flare.
  • Adding new mesh light on existing geometry during IPR results in double geometry.
  • Motion blurred polygons do not motion blur normals when deformed. Use Subdivision meshes instead.
  • When attempting to access an array primvar, you must first check the size of the array primvar and allocate the appropriate space. Not doing so may lead to a crash.
  • Points and curves cannot be used as geometric lights.
  • Analytical lights placed inside non-aggregate volumes may yield artifacts when made visible to the camera. As a work around, the light camera visibility should be turned off, and a geometry with a similar shape should be used (visible to camera, invisible to transmission and indirect rays), with the proper emissive bxdf.
  • Indirect Path Guiding in the PxrUnified integrator causes a crash.
• Bridge Products:
  • RfH: Soloing MaterialX Lama nodes in complex shading networks can give an incorrect result.

RenderMan XPU™

Please refer to the XPU section of the documentation for the current list of limitations.