Selected Bibliography Architectural Graphics | Page 101

PERSPECTIVE VARIABLES The observer's point of view determines the pictorial effect of a perspective drawing. As this viewpoint changes-as t heobserver moves up or down, to the left or right, forward or back-the extent and emphasis of what the observer sees also changes. In order to achieve the desired view in perspective, we should understand how to adjust the following variables. Height of the Stotion Point The height of the station point (SP) relative to anobject determines whether it is seen from above, below, or within its own height. • For a normal eye-level perspective, SP is at the standing height of a person. • As SP moves up or down, the horizon line (HL) moves up or down with it. • A horizontal plane at t he level of SP appears as a horizontal line. • We see the tops of horizontal surfaces that arebelow the level of SP and the undersides of horizontal planes that are above. ·~ • Even if not actually visible in aperspective view, the horizon line should always be drawn lightly across the drawing su rface to serve as alevel line of reference for the entire composition. PERSPECT IV DRAWINGS/ 95 E