Selected Bibliography Architectural Graphics | Page 80

PARALINE DRAWINGS Para line drawings commun icate the three-di mensional nature of anobject or spatial relationship in a single image. Hence, t hey are also called single-view drawings to distinguish them from the m ultiple and related views of plans, sections, and elevations. They can be distinguished from the other type of single-view drawing, linear perspective, by the following pictorial effects. - - - Parallel lines, regardless of their orientation in t he subject, remain parallel in the drawn view; they do not convergeto vanishing points as in linear perspective. ___ _ _. Any linear m easurement pa rallel to one of the three major axes~along axial lines-can be made and drawn to a consistent sca le. Axial lines naturally form a rectangular grid of coordinates that we can use to find any point inthree-d imensional space. ,. Nonaxiallines refer to those lines that arenot pa rallel to any of the three principal axes. We cannot measure dimensions along these nonaxial lines, nor can we draw them to scale.To draw nonaxial lines, we must first locate their end points using axial measurements and then connect t hese points. Once we establish one nonaxial line, however. we can draw any line parallel to that line, since parallel lines inthe subject remain parallel inthe drawing. / • Para linedrawings present either an aerial view looking down on an object or scene, or a worm's-eye view looking upward. They lack the eye-level view and picturesque quality of linear perspectives. They represent what we know rather t han how we see, depicting an objective reality that corresponds moreclosely to the picture in the mind's eye than to the retinal im of linear age perspective. 74 /ARCH ITECTURAL GRAPHICS