Selected Bibliography Architectural Graphics | Page 108

DIAGONAL POINT METHOD Plan Setup I, \ \ \ \ \ \ ·. ~ \ \ ~I I I \ \ \ ~·-Cllm:t \ OF~ I I I I I I I I I I I I • Before beginning the construction of any perspective, we should first determine the desired point of view: What do we wish to illustrate in the perspective view and why? • After we determine the space we are going to illustrate, we next establish the station point (SP) and the central axis of vision (CAV) in the plan view. • Because this is a one-point perspective, CAV should be parallel to one major axis of the space and perpendicular to the other. • We locate SP within the space but far enough back that the majority of the space lies within a60° cone of vision. • SP and CAV should be located off-center to avoid constructing a static, symmetrical perspective image. • For ease of construction, we can locate PP coincidental with a major plane perpendicular to CAV. Constructing the Perspective Grid • We start by deciding on a scalefor the picture plane (PP), taking into consideration both the dimensions of the space and the desired size of the perspective drawing. PP need not be drawn at the same sca leas the plan setup. --...... At the sca le of PP, we establish the ground line (GL) and the horizon line (HL) at the height of the eye level of the observer, that is, the station point (SP) above the ground plane (GP). ~~ · We establish the center of vision (C) on HL. The position of C can be determined from the plan setup. / Along G , we lay out to scale equal increments of L measurement. The unit of measu rement is typically one foot; we can, however, use sma ller or larger increments depending on the sc