PERSPECTIVE DRAWINGS
Perspective Projection
Perspective projection portrays a three-dimensional formor
construction by projecting all of its points to a picture plane (PP)
by straight lines that converge at a fixed point representing a
single eye of the observer.
• W we normally see through both eyes inwhat
hile
w call binocular vision. perspective projection
e
assumes we view at hree-dimensional subject or
scene through a singleeye, which we call the
st ation point (SP). Unlike the pa rallel projectors
inorthographic and oblique projections, the
pro
jectors or sightlines in perspective pro
jection
converge at this station point.
Pictorial Characteristics of Perspective Drawings
Theconverging sightlines inperspective give rise to
the two principal pictorial characteristics of
perspect ive drawings: convergence of parallel lines
and reduced size w distance.
ith
_,
_______...--------
• Pa rallel lines inthe subject or scene appear to
converge when they are perpendicular or oblique
tothe pictureplane (PP).
_ __. The size of an element or object appea rs to
decrease as it recedes from the observer.
ARCHITECTURAl DRAW ING SYSTEMS/ 31