Houdini 13.0


The Houdini Object Model (HOM) is an application programming interface (API) that lets you get information from and control Houdini using the Python scripting language. HOM replaces the functionality of Houdini’s previous scripting solutions, the expression language and HScript.

In Python, the hou package is the top of a hierarchy of modules, functions, and classes that define the HOM. The hou module is automatically imported when you are writing expressions in the parameter editor and in the hython command-line shell.


On Mac OS X and Linux, Houdini uses the system’s Python. On Windows, it uses the version of Python installed with Houdini.

On Linux, Houdini does not look at $PATH when trying to search and load the Python library. Instead it searches all the paths in $LD_LIBRARY_PATH, then /lib and then /usr/lib. If it can’t find a suitable Python library in the system, then it defaults to the one in $HFS. If your Python library is not in a standard location, you should add its directory path to $LD_LIBRARY_PATH.