You can manipulate a perspective drawing by changing certain variables, such as:
- moving the picture plane
- changing the orientation
- changing the station point location with respect to the object
- moving the horizon line up and down
The picture plane and the orientation remain fixed
The horizon line and station point with respect to the ground plane move up and down. As they move up, an aerial view of the pyramid becomes apparent.
The picture plane, the station point location, and the horizon line remain fixed. As the plane of the pyramid sides turns away from the picture plane, you see less of its surface.
Variable picture plane
Move the picture plane away from or closer to the observer. The station point location, the horizon line, and the orientation remain fixed.
Variable station point
The picture plane, the orientation, and the horizon line remain fixed. The station point location changes.