HtoA 6.4.3.1 - Arnold for Houdini
27 August 2025
HtoA 6.4.3.1 is a bugfix release using Arnold 7.4.3.1. For the full list of features in HtoA 6.4.3.0, see the HtoA 6.4.3.0 release notes.
Important: The Arnold 7.4.3.x releases are the last Arnold releases that will include support for CentOS 7.
Bug Fixes
- 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-16569 - AiProceduralExpand does not work with triggers_reinitialize
- ARNOLD-16576 - MaterialX documents containing textures with UDIMs and relative paths do 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-16752 - Geometry changes are not reflected in the scene bounding box
- ARNOLD-16576 - MaterialX documents containing textures with UDIMs and relative paths does not render
- usd#2349 - Fix Husk renders using the Arnold product type overwriting the same output path when rendering multiple frames in same proces
- usd#2392 - Fix a warning due to additional metadata parameters, typeName, and colorSpace introduced in USD 25.05
Installation
Download Arnold for Houdini from your Autodesk Account. See Download Arnold for more information about downloading HtoA from your Autodesk Account.
Follow these installation instructions
System Requirements
- Houdini, Houdini FX, Houdini Indie and Houdini Education
- 19.5.805
- 20.0.896
- 20.5.684
- Linux with at least glibc 2.28 and libstdc++ 9.3.1 (gcc 9.3.1) for Houdini 19.5, 20 and 20.5. This is equivalent to RHEL/CentOS 7.
- Linux with at least glibc 2.17 and libstdc++ 11.2.1 (gcc 11.2.1) for Houdini 20/20.5. This is equivalent to Rocky 8.
- macOS 11 or later
- Apple Mac models with M series chips are natively supported by HtoA
- x86-64 CPUs need to support the SSE4.1 instruction set. Apple Mac models with M series chip are supported natively mode.
- GPU rendering works on Windows and Linux only and requires 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.
- Optix™ denoiser requires an NVidia GPU with CUDA™ Compute Capability 5.0 and above.
- Intel OIDN GPU support is limited to:
- MacOS
- Apple native CPUs (M1 and newer)
- Windows
- Intel Xe dedicated and integrated GPUs
- NVIDIA GPUs using Turing or newer architectures
- MacOS