HtoA 6.4.2.3

2 July 2025

Arnold for Houdini 6.4.2.3 uses Arnold 7.4.2.2 and is a minor feature release.

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

• ARNOLD-13885 - Arnold GPU does not match CPU for polymesh.matte

• ARNOLD-14922 - Matrix modification of child object matrix in procedural_update is randomly ignored

• ARNOLD-15574 - Broken Cryptomatte due to NVIDIA compiler/driver float bug starting with 553.09

• ARNOLD-16333 - MaterialX relative path does not work with Arnold

• ARNOLD-16328 - Bucket corners stay at the end of the rendering in ARV with imagers

• ARNOLD-16410 - Numerical precision error in camera shutter_curve when almost 1

• ARNOLD-16415 - Don't reinterpret_type the pointers

• ARNOLD-16418 - Crash when adding objects to a funcptr procedural

• ARNOLD-16492 - Regression in procedural destruction time

• usd#2340 - Fix warnings when nodes are deleted during batch sessions

• usd#2334 - Fix random crashes with husk and cryptomatte

System Requirements

• Houdini, Houdini FX, Houdini Indie and Houdini Education
  • 19.5.805
  • 20.0.896
  • 20.5.613
• 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