Changes to file handling in iOS apps

As of version 19.10, both Algernon and CASA Space Frame 3D now use the standard iOS Document Browser for the handling of files. As such, there is now a minimum requirement of iOS 12.1 for these and future versions of the apps.

The document browser replaces the previous app-specific scheme for creating new models, saving, loading, and renaming. Files may also be exported and imported to/from the device through the document browser too, but the Utilities tab still has a dedicated Export function via e-mail to support other file formats (e.g. DXF in Algernon).

After a file is opened, you can return to the document browser by tapping on “Documents” at the top-left of the screen in the Utilities tab. Saving and discarding of files is now done in the document browser.

At the top-left of the document browser window there is a button called “Session”. This opens the menu from which the current session can be re-opened, saved, discarded, or closed.

When a file is opened in the app, it becomes the current session, and remains the current session until the user closes it. Other files cannot be opened while there is a current session.


If on the first run after updating the app, the document browser opens in the “iCloud Drive” location, tap on “< Locations” at the top-left of the screen, choose “On my iPad” in the left-hand menu, then tap on the relevant directory for the app (e.g. “Algernon” or “CASA SF-3D”). Occasionally on a first-run after an update, if the directory appears empty, quit the app and restart it (this appears to be an iOS bug which occurs only once).