Arnold for Maya 5.5.4 (What's New in Maya 2026.3)

Faster rendering with Global Light Sampling

Scenes using Global Light Sampling, render up to 2.5x faster in our tests. The numbers below are for same-noise renders. (ARNOLD-13091)

Improved Global Light Sampling (GLS) on glossy material in GPU renders

GPU renders (like CPU renders since Arnold 7.3.7.0 now take material glossiness into account when sampling, which greatly enhances the quality especially when many small lights are present. In the robot scene below, we get a ~3x speedup with adaptive rendering. (ARNOLD-15833)

Faster volume rendering on GPU

Scenes with volumes render up to 3.3x faster. Scenes with OpenPBR materials render up to 1.2x faster. (ARNOLD-11077, ARNOLD-16304)

Inference Imager

The >Inference imager is capable of performing inference on image-to-image machine learning models using the ONNX framework. (ARNOLD-16071)

Improved thin-walled subsurface in OpenPBR

When an instancer contains lights, it now takes their local matrix into account if instance_inherit_xform is enabled. The OpenPBR subsurface lobe in the thin-walled mode uses subsurface_weight to blend between diffuse and subsurface lobes while maintaining energy conservation. You can use this, for example, to model diffuse transmission and reflection in paper. (ARNOLD-15982)

Energy conserving metal in OpenPBR

The OpenPBR metal lobe now conserves energy and passes the furnace test. (ARNOLD-16327)

Improved HTML reports

The Arnold Render Report now supports sorting of statistics, displays the stats of the final render only, and has improved styles for resizing charts and tables. (ARNOLD-15600, ARNOLD-16011, ARNOLD-16562)

Renders automatically create output directories

Any time you render (for example, with kick or a DCC command-line process), the Arnold output drivers will automatically create any output folders that do not already exist. (ARNOLD-3476)

Imager Optimizations

Imager framebuffer management has been improved to reduce overhead between imager chains. This is especially noticeable when handling many imager chains. For example, in a 4096 x 2160 resolution render, we see the overhead between imager execution reduced by 4x when compared to Arnold 7.4.2.2, saving about 1 second per imager chain. (ARNOLD-16261, ARNOLD-16264, ARNOLD-16281)

Improved interactivity

Interactive render performance is improved, especially for camera moves and lighting changes. (ARNOLD-16200)

CPU fallback when no supported GPU found

Arnold falls back to CPU rendering according to the value of the render_device_fallback option when there are no supported GPUs. (ARNOLD-16277)

Improvements in geometry stats

Memory usage for top-level objects is now correctly calculated, and a new entry was added in memory stats. (ARNOLD-16350)

One-to-one path mapping rules

The Arnold pathmap file now supports one-to-one mapping rules, which offers a simple method to replace exact path references. The rules are defined within the path_map section of the JSON file. (ARNOLD-16351)

{
    "path_map": {
        "linux": {
            "S:/textures/plastic_basecolor.exr": "plastic_basecolor.exr",
            "S:/textures/plywood_normal.exr": "/mnt/plywood_textures/01/normal.exr"
        }
    }
}

Override output directory in kick

The kick command has a new argument-od that specifies an output directory path. This output directory is created if necessary, and added as a prefix to the output filenames specified by drivers in the scene. (ARNOLD-16513)

Light visibility in procedurals

You can now disable all lights in a procedural by setting the procedural visibility to 0. Any non-zero visibility enables the lights. This is evaluated per-instance, so you can disable lights for some procedural instances and enable them for others. (ARNOLD-16206)

OpenColorIO Aliases

You can now use OCIO aliases such as srgb_texture as input color spaces. The builtin OCIO config also supports the srgb_texture alias as well as other tweaks to be compatible with Maya 2026.2. (ARNOLD-16465, ARNOLD-16467)

MaterialX 1.39.3

The MaterialX version is now 1.39.3, upgraded from 1.38.10. Consult the full MaterialX release notes for more details. (ARNOLD-16361)

USD Enhancements

• DomeLight texture, color, and temperature combinations: When a DomeLight primitive has a color along with a texture or temperature enabled, these features combined, instead of being mutually exclusive. usd#1405
• Volume shaders on points: Volume shaders are now supported when assigned to point primitives in Hydra usd#2310
• Overwrite stats mode: Overwrite mode for stats and deprecate the render setting stats:modeusd#2320
• Moving the timeline optimized in the procedural: When the current frame is modified, the procedural is no longer re-initialized automatically. This can provide faster updates in Maya or 3dsMax stage objects with animated usd files, as only the animated primitives are updated. usd#2352
• USD 25.05: Arnold USD now uses USD 25.05. See the USD release notes for more information.

API changes

• Print a warning when a node is removed in batch mode: A warning is printed when a node is removed during scene update in batch render mode. In most cases, removing nodes in batch sessions can cause problems, and should be done in interactive render mode. (ARNOLD-16078)
• Deprecated AiStatsSetMode() and AiStatsGetMode(): Arnold now always overwrites the stats in the specified .json file. These API calls still work, but they now print a warning, and will eventually be removed. (ARNOLD-16413)
• Removed AtGPUCachePopulateCallback, AtGPUCachePopulateMode: The AtGPUCachePopulateCallback function type and the AtGPUCachePopulateMode enum became obsolete after Arnold was upgraded to OptiX 8 and are no longer used in the Arnold API. This does not require a recompilation of plugins. (ARNOLD-16229)

Incompatible changes

• Automated output directory creation: Arnold now attempts to create missing directories for drivers instead of erroring out. (ARNOLD-3476)
• Visibility of lights in a procedural: Lights in procedurals are now affected by the visibility parameter. (ARNOLD-16206)
• Removed options.gpu_max_texture_resolution parameter: The GPU maximum texture resolution feature was removed in a previous version of Arnold, so the parameter no longer did anything. (ARNOLD-16272)
• Removed ability to append stats using -statsfile: The kick -statsfile flag now always overwrites stats in the specified .json file. (ARNOLD-16377)

Bug Fixes

• MTOA-2411 - Autotx regenerates tx files created by Tx Manager
• MTOA-2422 - Fixed incorrect bounds metadata written into .ass files
• MTOA-2428 - Crash in instancer translator when mixed with particle instancers
• MTOA-2429 - MtoA fails to unload due to viewport.py error
• MTOA-2527 - MaterialViewer freezes Maya on Linux and MacOS
• MTOA-2555 - Inference imager displays incorrectly in Imagers editor UI on macOS
• ARNOLD-16317 - Corrupt BVH was generated in certain rare situations, resulting in crashes or missing objects
• ARNOLD-16439 - Removed "missing parallel_init metadata" warning for funcptr procedurals
• ARNOLD-16506 - Cryptomatte filter was not reflecting interactive changes in the beauty filter
• ARNOLD-16525 - Fix 7.4.2.1 performance regression when opening textures
• ARNOLD-16530 - Fixed errors with indexed normals in alembic files
• ARNOLD-16549 - Rare crash during GPU JIT compilation
• ARNOLD-16563 - Formatting errors for tables and stats in the Arnold Render Report
• ARNOLD-16569 - AiProceduralExpand does not work with triggers_reinitialize
• ARNOLD-16576 - MaterialX documents containing textures with UDIMs and relative paths do not render
• ARNOLD-16576 - MaterialX documents containing textures with UDIMs and relative paths does not render
• ARNOLD-16591 - GPU update is slow with negative progressive rendering and high AA
• ARNOLD-16612 - Very large unnormalized lights can have NaN in bounds
• ARNOLD-16615 - Only reevaluate procedural instancing optimization when scene is modified
• ARNOLD-16622 - Modified lights in IPR are not properly accounted for with global light sampling
• ARNOLD-16627 - Renderview rendering crashes when initializing log window
• ARNOLD-16695 - MaterialX Color4 Image node throws error while rendering
• ARNOLD-16713 - Support normalmap shaders from older versions of materialx
• ARNOLD-16723 - Support materialx_types in AiMaterialxGetNodeEntryFromDefinition
• ARNOLD-16752 - Geometry changes are not reflected in the scene bounding box
• ARNOLD-16761 - Crash when largest polygon stats contains deleted mesh
• ARNOLD-16770 - Scene bounding box is not updated for changes that reinitialize a geometry node
• ARNOLD-16772 - Nested procedural instances randomly disappear when GPU rendering on Linux
• usd#2307 - DomeLight connections are taken into account twice when written from an Arnold scene
• usd#2337 - Don't disable CER error reports through the hydra procedural
• usd#2346 - Node registry should consider arnold usd.hide metadata instead of DCC-specific ones
• usd#2333 - Fix crash in USD writer when the output string contains asterisks
• usd#2349 - Fix Husk renders using the Arnold product type overwriting the same output path when rendering multiple frames in same proces
• usd#2364 - Fix render delegate crash when using indexed UVs and shared arrays
• usd#2392 - Fix a warning due to additional metadata parameters, typeName, and colorSpace introduced in USD 25.05
• usd#2422 - Fix regression on frame changes in the usd procedural

System Requirements

• Maya 2024, 2025, or 2026
• Windows 10 or later, with the Visual Studio 2019 redistributable.
• Linux with at least glibc 2.17 and libstdc++ 4.8.5 (gcc 4.8.5). This is equivalent to RHEL/CentOS 7.
• x86-64 CPUs need to support the SSE4.1 instruction set.
• macOS 10.13 or later, macOS 11 and later for Maya 2024
• Apple Mac models with M series chips:
  • Natively supported by Arnold for Maya 2024
  • Supported under Rosetta 2 mode for older versions of Maya
• GPU rendering and Optix denoising work on Windows and Linux only, and require an NVIDIA GPU with the Maxwell architecture or later.
  • On Linux, we recommend 570.153.02 or higher drivers.
  • On Windows, we recommend 573.42 or higher drivers.
• Intel OIDN GPU support is limited to:
  • Apple native CPUs (M1 and newer)
  • Intel Xe dedicated and integrated GPUs
  • NVIDIA GPUs using Turing or newer architectures
  • AMD GPUs with RDNA2 (Navi 21 only) and RDNA3 (Navi 3x) architectures