Fig. 307.
[Figs. 307] and [308] show, in two cases, how these three views would appear. The end views are those where the perspective picture appears on the plane, while the top and side views only show where the rays intersect the picture plane. The top view shows how far, for example, point A is distant from a vertical line O Z, while the side view shows how far point A is below horizontal line O X, which is at the same height above the ground as the eye of the observer, O. Thus, all points of the cube can be located on the picture plane, and the outlines of the cube reproduced in perspective.
Fig. 308.
Modified arrangements are shown in [figs. 309] and [310] for parallel and angular perspective.
Fig. 309.
The views are so arranged in relation to each other that the picture plane in the top view is parallel to the horizon and the ground-line, which latter is the intersection of the picture plane with the level ground of the end or perspective view. At the same time the eye of the observer is in one and the same vertical line for both views, two vanishing points may be found in the horizon outside of the principal visual ray. To find the position of these two vanishing points in the picture plane, the modified top view, [fig. 310], is used.
Fig. 310.