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6.5.1 Saving considerations
6.5.2 History and snapshots

6.5 Save and load U-splines with Cubit file

U-Splines generated in Coreform Cubit are saved along with the associated Cubit model as part of Cubit’s native HDF5 .cub5 file. The saved U-spline model state can then be re-opened in U-spline-enabled versions of Cubit.

6.5.1 Saving considerations

U-Spline data can be saved only to .cub5 files in the Cubit HDF5 file format. If a U-spline model is saved to a non-HDF5 format, the U-spline data will not be saved, and will be lost when the session is reset or closed.

Cubit .cub5 files containing U-splines can be opened in versions of Cubit (such as Sandia Cubit) that do not include U-spline functionality, but U-spline data will be ignored.

6.5.2 History and snapshots

The U-spline data saved to an HDF5 .cub5 file includes both a history of Coreform IGA commands and periodic snapshots of the U-spline output.

A sequential history of IGA commands is automatically saved to the .cub5 file when a U-spline is saved. This provides a history of the model and supplies groundwork for future development of advanced features like undo/redo and version control.

For efficiency, Cubit also saves periodic snapshots of the current state of the U-spline model, consisting of the JSON export data for the model at the time of snapshot.

When a U-spline .cub5 file is opened, the U-spline model data is populated by the most recent snapshot, after which any subsequent history commands are re-executed.