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Known Issues

Known Issues

Owned by Eugene Riecansky
Last updated: Apr 02, 2025 by Sarah Forcier
4 min read

Installation + Licensing

  • macOS 11 and beyond: 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.  RMAN-18802

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.

Denoiser

  • macOS/Apple Silicon: The denoiser is not supported on Apple Silicon, even with Rosetta.  RMAN-20408

  • If your image has NaNs from either RIS or XPU, the denoiser will fail on macOS and Windows. 

  • The interactive denoiser currently is not supported in XPU.

  • The progress bar in the Denoise App doesn’t currently work. RMAN-23054

XPU

  • The GPU portion of XPU can render artifacts with trace:reflectexcludesubset.  RMAN-20393

  • Support for homogeneous single scattering in PxrSurface is incomplete. Renders will be noticeably incorrect after the first bounce off the interior of a closed object. RMAN-16374

  • Lights inside objects with homogeneous single scattering in PxrSurface will not compute the correct shadows. RMAN-16367

  • Due to differences in how XPU computes derivatives for normals, XPU may compute different results from RIS for bump mapped subdivision surfaces in areas of highly concave curvature, combined with a high bump scale. This happens especially when the bump mapping cannot reasonably approximate the displacement. Note that this difference does not occur with displacement. The issue can be ameliorated by reducing the bump scale. RMAN-21977 

  • Please refer to the XPU section of the documentation for a more detailed current list of limitations.

RIS and XPU

  • Color Management: Although we have upgraded to the VFX Reference Platform 2023, there is an outstanding issue with the Image Tool described below.

The Image Tool is currently unable to read OCIO v2 configurations and is locked to the $RMANTREE/lib provided configuration. If you have a v1 config you would like to use set the environment variable IT_OCIOV1.

  • MaterialX: Material layering is not supported.  RMAN-20365

RIS

  • Shading

    • PxrUnified integrator 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.

    • The RixTexture::TextureDerivatives calls always returns RixTexture::InvalidFile for non-texture-atlas files. This will be restored in 26.1.

  • General rendering

    • Load on demand procedurals are not supported anymore, all procedurals are now loaded immediately.

    • RenderMan does not read point data from OpenVDB files.

    • Per-Instance baking is not supported, only the reference instance.

    • 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 for Houdini

  • When batch rendering from a RIB exported from Houdini, the searchpath may contain an invalid path that causes RenderMan to load the wrong OpenVDB shared library, causing batch renders to fail.  The workaround is to edit the "procedural" searchpath in the RIB to $RMANTREE/lib/plugins instead of the one in the RenderMan for Houdini directory.  RMAN-20297

  • RfSolaris: Texture memory limits are not properly respected.  RMAN-20563

  • Denoise ROP does not work in H20, py3.10. In py3.9, it will work if loppath on the usdrender_rop LOP node is set to opinput('.', 0) - RMAN-21926

RenderMan for Maya

If you see any issues with PySide, please redownload RenderMan and RenderMan for Maya. A new 26.3 patch fixes these python issues.

  • F-Stop is divided by 10X with PxrCamera.  RMAN-20475

  • Overriding PYTHONPATH can cause denoising to fail.  RMAN-20546

  • Adding multiple AOVs whilst running RenderMan in the viewport can cause Maya to crash

  • When using the ROI tool and the interactive denoiser in Maya’s viewport can cause Maya to crash

  • Using the Interactive Denoiser in the viewport whilst in XPU is not supported yet and will display visual inconsistencies.

  • Maya Fluids are not supported.

 

RenderMan for Blender

  • Canceling a render from "it" will crash Blender. One workaround is to cancel the render from Blender.

  • Translating Cycles shading networks is not supported.

  • Not all curve types are supported.

  • Grease Pencil is not fully supported.

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