Plot Overlays Properties

To access these properties:

In the Sheets or Project Data control bar, right-click a projection's Overlays folder and choose Overlays Properties.
Display the Properties control bar and, in the Sheets or Project Data control bar, click a projection's Overlays folder and choose Overlays Properties.

General properties for managing overlays in plot sheet projections can be found here.

Automatically add new 3D object overlays: choose what happens when new object data is created (as a result of loading or importing data within a project session. You can select:

None: leave the existing overlays plot item as it is, without adding the new object data default overlay(s). You can load them later if you want to.
2D overlays: automatically add overlays of the legacy 2D type to the projection, once the data is loaded, providing the overlay group isn't locked (see below). See Projection Overlay Types.
3D overlays: add 3D overlays to a 3D Overlay Group and display them in the projection once data is loaded, providing the overlay group isn't locked (see below). See 3D Overlay Groups.

Remove empty overlays:

If Yes, overlays that don't contain 3D data (say, data has been unloaded) are automatically removed from the projection, providing the overlay group isn't locked (see below).
If No, empty overlays remain listed.

Make the current overlay collection available to other projections within the current plot sheet (Within sheet).
Make overlays available to other sheets of the same project (Within document).
Ensure overlays are only available to their parent projection, meaning they can be duplicated within the projection, but nowhere else (Not shared).

Note: If overlays are locked (that is, the Lock Overlays context menu option for a projection is enabled, so that a padlock appears against the overlays icon), then no overlay is created if new data is loaded, regardless of the settings made above.