PARALINE DRAWINGS
Oblique Projection
Oblique projection represents athree-dimensional form or
construction by projecting parallel lines at some convenient
angle other t han90° t o thepictureplane. Aprincipal face or
set of planes of the sub is usually oriented parallel t o
ject
the picture plane and is thereforerepresented in accurate
size, shape. and proportion.
• For convenience, t he receding lines perpendicular t othe
picture planeare typically drawn to the sam scale as t he
e
lines parallel to the pict ureplane.
• The recedinglines may beforeshortenedt o3f4 or 1/2 their
true scaled lengtht o offset t heappea ranceof dist ortion.
In architectural drawing, t here are two principal types of
obliquedrawings: planobliques and elevat ion obliques.
P O
lan bliques
• Plan obliques orient the horizont al planes of t hesubject
parallel to the pict ureplane. These horizontal planes are
t herefore shown in t rue size and shape, while thetwo
principal set s of vertical planes are foreshortened.
• P obliques have a higher angleof view than isom
lan
etric
drawings.
• Anadva ntageinconstructing plan obliques isthe ability
to use floor plans as base drawings.
E
levation Obliques
• E ionobliques orient one principal set of vertica l
levat
planes of the sub parallel to the picture plane. This set
ject
is t herefore shown in true size and shape, whilethe other
vertical set and the principal horizon al set of planesare
t
b foreshortened.
oth
• Thefaceselected to be parallel tothepicture planeshould
be t helongest, the most complex, or the most significant
faceof t he buildingor construction.
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I ARCHITECTURA L GRAPHI CS