HtoA 6.4.2.1 - Arnold for Houdini

30 May 2025

Arnold for Houdini 6.4.2.1 is a bugfix release that uses Arnold 7.4.2.0. For the full list of features in HtoA 6.4.2, see the HtoA 6.4.2 release notes.

Installation

• Download Arnold for Houdini from your Autodesk Account. See Download Arnold for more information about downloading Arnold for Houdini from your Autodesk Account.

• Follow these installation instructions.

Bug Fixes

• HTOA-2907 - Fixed classic HtoA IPR on Mac (caused by incorrect rpaths)
• HTOA-2138 - Import materials now sets uv_projection.matrix properly
• HTOA-2902 - Arnold ROP no longer explicitly checks if a directory is writable when Create Intermediate Directories is set

System Requirements

• Houdini, Houdini FX, Houdini Indie and Houdini Education
  • 19.5.805
  • 20.0.896
  • 20.5.584
• 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 560.35.03 or higher drivers.
  • On Windows, we recommend 560.76 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