Known Limitations

Mismatched USD Versions between Houdini and Create

Houdini uses a newer version of USD than Omniverse USD Composer. This mismatch causes problems where there is a lack of backward compatibility. One such case exists for the inputs: prefix included in light prim attribute names. Because this prefix is not backwards-compatible, this prefix does not work in Omniverse USD Composer. As a workaround, use the set_legacy_light_properties LOP before you export your USD to Omniverse USD Composer. When exporting from Omniverse USD Composer to Houdini, perform the opposite action using the Upgrade Old Light Primitives LOP.

Houdini Digital Assets (HDAs)

HDAs cannot be saved to or loaded from Omniverse Nucleus server paths. A file copy utility tool is provided to copy files to and from Nucleus.

Make Numbered Backups

Houdini’s Make Numbered Backup save method preference doesn’t work with Omniverse Nucleus paths. You’ll see an error, and our post-save callback will provide a workaround.

Workarounds:

  • Use the provided save command from the Omniverse menu and Shelf

  • Switch from the default preference to Overwrite File or Increment Filename

Note

For versioning of your .hip file, you will automatically receive Nucleus checkpoints when working with .hip files on Omniverse Nucleus servers with the checkpoint feature turned on.

Create Directories

Creating directories from Houdini’s File Chooser Dialogs is not supported in Houdini 19.0. This is due to a limitation in Houdini 19.0 HDK. This was addressed in later Houdini versions.

Workarounds:

  • Please create new directories from Nucleus, Houdini 19.5 and/or later Houdini versions.

Create Directories

Creating directories from Houdini’s File Chooser Dialogs is not supported in Houdini 19.0. This is due to a limitation in Houdini 19.0 HDK. This was addressed in later Houdini versions.

Workarounds:

  • Please create new directories from Nucleus, Houdini 19.5 and/or later Houdini versions.

VDB Volume Sequences

VDB Volume Sequences are not currently supported by Omniverse USD Composer. Support for VDB Volume Sequences is in active development, and NVIDIA expects to announce OpenVDB support soon.

Load Warnings

You may see warnings regarding unrecognized parameters when you load a .hip file that was saved from a different Houdini version. This is usually harmless and can be ignored. Using Houdini Omniverse Connector with Houdini 20 provides the smoothest experience.

Workarounds:

  • Houdini provides an environment variable $HOUDINI_DISABLE_FILE_LOAD_WARNINGS to suppress the load warnings.