HtoA 3.0.2

5 June 2018


This is a feature release, providing support for primitive attributes on packed alembics, support for displacements on alembics, and fixing alembic issues in the core procedural.  Shape primitive attributes should be prefixed with ar_, and other primitive attributes are exported as user data.  An Arnold denoiser ROP is also provided to run noice, and the AOVs it requires are created automatically.


  1. Get the install files on Solid Angle Downloads.
  2. Follow these installation instructions.


This release uses Arnold and OpenVDB 4.0.0.

Binaries available for the following Houdini, Houdini FX, Houdini Indie and Houdini Education production builds:

  • 16.5.405
  • 16.5.439
  • 16.5.473
  • 16.5.496


and for the following platforms:

  • Linux x86_64 (gcc4.8)
  • Windows 7 x64 (vc14)
  • Mac OS X 10.8+ (clang7.3)


Please note that Houdini Apprentice does not support third-party renderers and thus cannot run HtoA.


  • Translate alembic packed primitive attributes as user data (htoa#1009)

  • Pull Arnold parameters from alembic packed primitives (htoa#1041)

  • Create noice denoiser ROP (#1025)

  • Add extra AOVs for noice automatically (htoa#1024)

  • Add extra AOVs coming from the hair, standard, toon shaders to the ROP AOV list (htoa#1026)


  • Match number of motion keys for normals and vertex list in alembic procedural (core#6909) 

  • Add facevarying userdata support to alembic procedural (core#6937) 

  • Fix for indexed normal and uv properties in alembic files that use instancing (core#7034)

  • Array properties in alembic procedural not translated (core#7025) 

  • Fix displacement override in the alembic procedural (core#7059)

  • Don't use AiDevice API if OptiX denoiser is not enabled (htoa#1045)

  • Link to help pages for Operator nodes (htoa#1033)

  • Setting AOV to a different filter supported fixed (htoa#1031)

  • Set camera shutter to zero on alembic procedurals if the motion blur is disabled on the ROP (htoa#1011)

  • Auto curve translation fixed (htoa#1020)

  • Fix displacement for packed alembic files (#1028)

  • Fix operator subnet connections (#1043)
  • Make image shader multiply input linkable (#1046)
  • invDepth aov transmission bug (#998)
  • Enabling transmission affects rayDepth AOV (core#6735)


See also the Arnold release notes for the full list of core enhancements and fixes.


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