HtoA 6.4.5.1

19 November 2025

HtoA 6.4.5.1 is a bugfix release using Arnold 7.4.4.0. For the full list of features in HtoA 6.4.5.0, see the HtoA 6.4.5.0 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

• HTOA-3051 - Automatic TX generation is not working in viewport renders
• usd#2473 - Fix regression in default value of texture_auto_generate_tx in the render delegate

System Requirements

• Houdini, Houdini FX, Houdini Indie and Houdini Education

  • 20.0.896
  • 20.5.684
  • 21.0.512

• 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 580.95.05 or higher drivers.
  • On Windows, we recommend 581.42 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