You can define a viewing direction by entering the coordinate values of a point or the measures of two angles of rotation.
This point represents your position in 3D space as you view the model while looking toward the origin (0,0,0). Viewpoint coordinate values are relative to the world coordinate system unless you change the WORLDVIEW system variable. The conventions for defining standard views differ between architectural (AEC) and mechanical design. In AEC design, the perpendicular view of the XY plane is the top or plan view; in mechanical design, the perpendicular view of the XY plane is the front view.
You can rotate a view using DDVPOINT. The following illustration shows a view defined by two angles relative to the X axis and the XY plane of the WCS.