HtoA 6.4.2.2 - Arnold for Houdini

9 June 2025

Arnold for Houdini 6.4.2.2 uses Arnold 7.4.2.1 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.

ARNOLD-15719 - Crash when triplanar.smooth_before_displacement is passed to displacement
ARNOLD-16065 - Multipart render fails because parts do not have unique names
ARNOLD-16157 - Lights in moved procedurals instances are not properly moved
ARNOLD-16203 - Failures and crashes when rendering to exr in append mode
ARNOLD-16234 - Crash when rebuilding an instanced object
ARNOLD-16253 - Publishing compounds with custom arnold nodes does not render
ARNOLD-16289 - Updated the metadata for the density, roundness, width_edge, height_edge, and ramp parameters of the light blocker shader
ARNOLD-16299 - Ensure that a procedural's bounding box is computed after all child nodes are updated
ARNOLD-16301 - Improve clarity of GPU error messages when CUDA fails to load
ARNOLD-16344 - Incorrect scene unit conversions when processing procedurals in procedural cache
ARNOLD-16347 - Crash when using an invalid filename on an instanced procedural
usd#2296 - Proper support of stats mode in the render delegate
usd#2303 - Improve detection of hidden primitives that should be skipped
usd#2309 - Fix recent conflict between primitives visibility and purpose
usd#2313 - Arnold primvars aren't taken into account for ArnoldProceduralCustom primitives in usd

Houdini, Houdini FX, Houdini Indie and Houdini Education
- 19.5.805
- 20.0.896
- 20.5.584
- 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 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