When rendering perspective views from real objects or models, the view can be controlled only within certain limitations. The great advantage of constructing or making a perspective is that virtually any view can be represented, even if such a view would be impossible to see in a real situation.
In order to construct perspective views, it is necessary to take into consideration four interconnected variables that will affect the final image.
On the picture plane, eye level and the horizon are the same.
Thus, if an object is below the horizon line, the top side of the object will be visible.
If the object is divided by the horizon line, neither the top nor the bottom will be visible.
If the object is above eye level, the bottom of the object will be visible.
The position of the picture plane in relation to the viewer and the object affects the overall size of the object within the frame, but does not alter the proportions or angles of the image. For the purpose of setting up plans and perspective views, ...