HtoA 6.4.5.1 - Arnold for Houdini

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

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

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