Operation

Operating of the 2D and 3D automatic mode is characterized by:
An impact on the interface and available commands.
The automatic change of view as per 2D and 3D modes.
Vice versa, automatic 2D or 3D display of model as per the view selected.
Impact on the Interface
While displaying the model in 2D
The icon Perspective is locked
The Display tool bar hides the icons enabling access to elevation or axonometric views:

Similarly, these commands are no longer accessible from the contextual menu.
NOTE: You can however use the pull-down menu or the hotkeys to access these views. Consequently, the model will be displayed automatically in 3D mode.
The work mode menu does not give access to the display modes:

NOTE: You can however use the hotkeys to access these views. Consequently, the model will be automatically displayed in 3D mode.
While displaying the model in 3D
The icon perspective is unlocked
The Display tool bar displays the icons enabling access to the elevation or axonometric views:

Similarly, these commands become accessible from the contextual menu.
The menu of the work modes displays access to the display modes:

View Management in 2D and 3D Modes
When the 2D and 3D automatic mode is activated, the management of views is as follows:
ActionResult
First 3D displayThe model is displayed in axonometric view
First 2D displayThe model is displayed in Zoom All plane
Next 3D displayThe last non orthogonal 3D view is restored
Next 2D displayThe last zoom on a portion of the plan view is restored
Plan view display2D display,
If the perspective was activated in 3D, it is automatically deactivated
Axonometric or elevation view3D display