Houdini 20.0 Python scripting

Alembic extension functions

Utility functions for extracting information from Alembic files.

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These functions are not part of “HOM proper”. They are not under the hou package and are not integrated into the object model. Future versions of Houdini may have better integrated support for working with Alembic data in Python.

To use the functions in this module, launch hython and import _alembic_hom_extensions.

>>> import _alembic_hom_extensions as abc
>>> print abc.alembicGetSceneHierarchy("panda.abc", "/")
('ABC', 'unknown', (('Geo', 'cxform', ...


  • Importing this module does not use a Houdini license.

  • While the functions work with file paths, they don’t open and close the files every time a function is called. The code keeps an internal cache of open Alembic files to make repeated calls on the same file efficient.

  • The tuple of 16 floats returned by getLocalXform and getWorldXform can be directly passed to the hou.Matrix4 constructor to create a hou.Matrix4 representation of the transform.

Common arguments


A file path to the Alembic file.


The path within the alembic file to the object.


The name of the attribute to read.


The animation time at which to compute the value. This is a fractional value in seconds. If you have a frame number you must divide by the frames-per-second before passing it to the function.


Python scripting

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  • hou

    Module containing all the sub-modules, classes, and functions to access Houdini.

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