9 August 2023

HtoA 6.2.3.0 is minor feature release using Arnold 7.2.3.0, it introduces native support for Apple Silicon.

Installation

• Download Arnold for Houdini
• Follow these installation instructions

Enhancements

• Apple Silicon Support : HtoA now natively supports Apple M1 chips for Houdini 19.5. In our tests, running natively on Apple M1 chips can give speedups of up to 1.45x compared to running with x86_64 Rosetta 2 translation. (HTOA-2010)

• Global light Sampling support on GPU: Global Light Sampling (GLS) is now available with GPU rendering. Many scenes with moderate to large number of lights render 2-6x faster with GLS. Scenes that do not benefit from GLS tend to be a few percent faster or slower. See the GLS documentation for important information on the optimal number of light samples to use with GPU. (ARNOLD-13109)

• Return direction and distance to nearest hit in distance shader: Arnold 7.2.3 adds out_distance and out_direction output parameters to the distance shader, which return the direction and distance to the nearest surface, respectively. The shader still returns the color-mapped result by default, which is now available as the out_rgb parameter. (ARNOLD-13473)

• state_float, state_int, state_vector multiple outputs: The shading state shaders now have multiple outputs, so you can use a single state shader with multiple output connections in a shading network. (ARNOLD-13579)

USD Enhancements

• Support vertex UV coordinates on Curves in the render delegate usd#1435
• Curves without width should render with a default value usd#1579

Bug Fixes

• HTOA-2244 - Fix the assignment of the cryptomatte shader by the Arnold RenderSettings LOP

• HTOA-2262 - Add reference_time param when calling AiProceduralViewport

• HTOA-2213 - Fixed an rpath error for Python3.7 Houdini 19.5 on Mac

• HTOA-2268 - AOVs are now visible in the Solaris render output menu when 'Arnold productType' is enabled

• HTOA-2257 - Match scene units of arnold_viewport_proxy to working scene

• ARNOLD-10643 - FIS no longer forces a box filter

• ARNOLD-12917 - Viewport API uses incorrect motion blur reference time

• ARNOLD-13645 - Instancer crash if a single node is instanced but set to null

• ARNOLD-13678 - Holes in alpha channel when opacity is almost 1

• ARNOLD-13741 - Log messages missing colors

• ARNOLD-13770 - Name scope clashes with nested procedurals

• ARNOLD-13776 - NaNs when using global light sampling with low-light-threshold

• ARNOLD-13789 - Corrupted tiff output if skip_alpha and unpremult_alpha are both enabled

• usd#1538 - Fix triplanar in USD MaterialX

System Requirements

• Houdini, Houdini FX, Houdini Indie and Houdini Education
  • 18.5.759
  • 19.0.720
  • 19.5.682
• Linux with at least glibc 2.17 and libstdc++ 4.8.5 (gcc 4.8.5). This is equivalent to RHEL/CentOS 7.
• macOS 10.13 or later, macOS 11 or later for Houdini 19.5
• Apple Mac models with M series chips:
  • Natively supported by Arnold for Houdini 19.5
  • Supported under Rosetta 2 mode for older versions of Houdini
• 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 of the Ada, Ampere, Turing, Volta, Pascal, or Maxwell architecture. We recommend using the 525.89 or higher drivers on Linux and 528.49, or higher on Windows. See Arnold GPU for more information.
• For GPU rendering, the cache also needs to be re-populated after installing a new Arnold version, updating to a new NVIDIA driver, or changing the hardware configuration of GPUs on the system. More information can be found here.
• Optix™ denoiser requires an NVidia GPU with CUDA™ Compute Capability 5.0 and above.