HtoA 6.4.3.1
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
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.
- 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