The Vertical Rotation is an angle in degrees away from a vertical through the terrain.
- When 0° is specified, the line of sight is perpendicular to the 3D view; the observer is located high in the sky and looks straight down on the 3D view.
- When 90° is specified, the line of sight is parallel to the 3D view; the oberver is located on the same height as the view point and sees the 3D view in front of him.