HtoA 6.4.6.2 - Arnold for Houdini

01 April 2026

HtoA 6.4.6.2 is a bugfix release using Arnold 7.4.5.2. For the full list of features in HtoA 6.4.6.0, see the HtoA 6.4.6.0 release notes.

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

Bug Fixes

• ARNOLD-13050 - Color manager could not find sRGB config with non-standard name
• ARNOLD-15293 - Append with multipart triggers ERROR when output file already complete
• ARNOLD-15504 - Missing update dependency for OpenPBR surface nits_per_unit
• ARNOLD-15631 - Crash when enabling autocrop with multipart/tiled EXR outputs
• ARNOLD-15889 - Rare crash when using .ass file with specific sizes and data
• ARNOLD-16573 - Maketx crash with TIFFs with malformed exif data
• ARNOLD-16749 - Random GPU crash
• ARNOLD-17416 - Incorrect results with autocrop and multipart
• ARNOLD-17429 - Fixed ARNOLD_ND_image MaterialX node definition input order mismatch that caused viewport shader compilation failure
• ARNOLD-17441 - Allow interactive changes for aperture bloom parameters
• ARNOLD-17451 - Crash in Linux with certain host processes
• ARNOLD-17500 - Crash with invalid "idxs" user data
• ARNOLD-17521 - Denoised outputs ignore driver's half precision
• ARNOLD-17524 - Random crash with pointclouds
• ARNOLD-17652 - Render files written on every pass for USD files

System Requirements

• Houdini, Houdini FX, Houdini Indie and Houdini Education

  • 20.0.896
  • 20.5.684
  • 21.0.596

• 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 supported in native mode

• x86-64 CPUs need to support the SSE4.1 instruction set.

• GPU rendering works on Windows and Linux only and requires driver versions newer than 582.16/580.126 (Windows/Linux). Older drivers will log an error and abort the render. Note that you can use New Feature Branch drivers.

  • On Linux, we recommend 590.48 or higher drivers.
  • On Windows, we recommend 591.28 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