HtoA 6.5.1.2
27 May 2026
HtoA 6.5.1.2 is a bugfix release using Arnold 7.5.1.2. For the full list of features in HtoA 6.5.1.0, see the HtoA 6.5.1.0 release notes.
Installation
Bug Fixes
- HTOA-3275 - Wrong overscan for some resolutions
- HTOA-3278 - Fix slow shader network updates
- ARNOLD-8717 - Interactive changes to a sphere center or radius are not transferred to its instances
- ARNOLD-12159 - Dispersion transmission incorrectly raises error_color_bad_pixel debug coloring (blue pixels)
- ARNOLD-14076 - standard_hair shading artifacts when used with non-curves objects
- ARNOLD-15737 - Fix Ctrl+C (SIGINT) being ignored when Arnold is run in background or automated runs
- ARNOLD-16842 - Modification of child object matrix in procedural_update is randomly ignored
- ARNOLD-17339 - Log messages that were intended to show up only once could show up multiple times
- ARNOLD-17411 - kick crashes when you render an ASS file that does not define any render outputs
- ARNOLD-17682 - Some node parameter changes can be randomly lost during scene update
- ARNOLD-17696 - Error when assigning MaterialX shader to a USD prim
- ARNOLD-17708 - Crash on process exit when Arnold library is loaded with deep bindings
- ARNOLD-17712 - SSS is broken with native instancing
- ARNOLD-17728 - Fix regression of rare crash when compiling OSL shaders during IPR
- ARNOLD-17748 - Fix random crashes/hangs at process exit and during rendering with network (NLM) licenses
- ARNOLD-17757 - Artifacts when using oriented curves with a scaled transform matrix
- ARNOLD-17766 - Point cloud cache causes a CUDA exception when used with multiple GPUs
- ARNOLD-17769 - Fix random crash/hang at process exit caused by AiMsg calls when missing AiEnd
- ARNOLD-17771 - Rare crash at process exit when using Arnold denoiser (noice) imager
- ARNOLD-17794 - GPU rendering issue with native shape instancing
- ARNOLD-17801 - Procedural instances sometimes do not render in conservative optimization mode
- ARNOLD-17803 - Rare crash when instancing procedurals
- ARNOLD-17807 - Random GPU crash in optixQueryFunctionTable after modifying objects
- ARNOLD-17808 - kick -o does not work if drivers NULL in ASS file
- ARNOLD-17817 - Kick output directory prefix is not applied when overriding the filename via
-set
- usd#2635 - Fix rounding issue with husk when overscan is used at certain resolutions
System Requirements
- Houdini, Houdini FX, Houdini Indie, and Houdini Education
- 20.0.896
- 20.5.684
- 21.0.700
- 21.0.729
- 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.
- 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