You can define a viewing direction by typing the coordinate values of a point or two rotation angles (angle from the XY plane and angle from the X axis).
The specified point indicates your position in 3D space when you view the model while looking toward the origin (0, 0, 0). The viewpoint coordinate values are relative to the WCS unless you modify the system variable WORLDVIEW.
The conventions for defining standard views are different among different industries. In architectural (ARC) design, the perpendicular plane of XY plane is the top view or plan view; in mechanical design, the perpendicular view is the front view.
DDVPOINT is designed to rotate views to specify a viewing direction.
The following illustration shows a view defined by two angles relative to the X axis and the XY plane of the WCS.
VIEW:Saves and restores named views
System Variables Reference
WORLDVIEW: Determines whether input to the DVIEW, and VPOINT commands is relative to the WCS (default) or the current UCS