HtoA 6.5.1.1

20 April 2026

HtoA 6.5.1.1 is a bugfix release using Arnold 7.5.1.1. For the full list of features in HtoA 6.5.1, see the HtoA 6.5.1 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-14348 - Fixed random crash while rendering on ARM64 machines

• ARNOLD-17656 - Fixed a hang when replacing a shader that was connected to a light

• ARNOLD-17660 - AiProceduralViewport crashes with implicit nodes

• usd#2607 - Updating light shaders interactively hangs the render

• usd#2613 - Missing clip files and UDIMs from search path when collecting scene assets

• usd#2615 - Export material bindings for volume nodes in the volume context

• usd#2589 - Implement scene index dependencies when materials get added or removed

• usd#2582 - Arnold-disabled nodes should not be authored to USD

• usd#2433 - Support interactive changes of shaders connected to quad lights

• usd#2611 - Support exporting geometries that get added during a sequence

System Requirements

• Houdini, Houdini FX, Houdini Indie, and Houdini Education
  • 20.0.896
  • 20.5.684
  • 21.0.671
• Flow Render is available for the default Houdini Qt versions ( Qt6 for Houdini 21, and Qt5 for Houdini 20.5 and Houdini 20.0)
• Linux with at least glibc 2.28 and libstdc++ 11.2.1 (gcc 11.2.1). 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.
• GPU rendering and OptiX denoising work on Windows and Linux only, and require an NVIDIA GPU with the Maxwell architecture or later.
  • On Linux, we recommend 590.48 or higher drivers.
  • On Windows, we recommend 591.28 or higher drivers.
• Intel OIDN runs on all CPUs. GPU support is limited to:
  • macOS
    • Apple silicon GPUs (M1 and newer)
  • Linux
    • NVIDIA GPUs with Turing, Ampere, Ada Lovelace, Hopper, and Blackwell architectures
  • Windows
    • Intel Xe and Intel Arc dedicated and integrated GPUs
    • NVIDIA GPUs with Turing, Ampere, Ada Lovelace, Hopper, and Blackwell architectures
    • AMD GPUs with RDNA 2, RDNA 3, RDNA 3.5, and RDNA 4 architectures