Clear UI mode
You can use the square bracket keys [ and ] to quickly clear and restore all UI elements in the viewer (e.g. the left panel, the map window). This can be useful for temporarily giving yourself a clear 3D view, and then being able to restore the UI back to its former state.
Use the left square bracket key [ to clear the viewer window of UI elements.
Use the right square bracket key ] to restore the UI to the state it was in before being cleared.