Use the View > 3D View Options > 3D Projection Settings command or the 3D Visualization toolbar’s button to open the two modes of this dialog box.
For general information, see 3D Projections.
The name and contents of the dialog box depend on the projection type: Parallel Projection Settings or Perspective Settings. You can easily switch from one settings dialog to the other with the button at the top right corner.
The projections that you define in the 3D Projection Settings dialog boxes remain valid only until the next time you open the dialog box and modify them.
Related Topics:
Perspective Projection Settings