Camera Visibility Persistance Between Sessions

[cam3d]

Currently there is no persistance of camera visibility settings, with camera visiblity forced on each time Zephyr is re-opened. It would be ideal for this setting to remain (either on or off) so that the user can open Zephyr without Camera positions visible if that is their preference.

As a checkbox in settings and/or via hotkey selection.

Suggested by Michael Manning via. helpdesk.