PAR ALINE DRAWINGS
A ometric Projec
xon
tion
An axonometric projection is an orthographic projection of a three-dimensional form that is inclined to
the picture plane in such away that its three principal axes are foreshortened. The term "axonometric"
is often misused to describe para line drawings of oblique projections or the entire class of para line
drawings. Strictly speaking, axonometric projection is aform of orthographic projection in which the
projectors are parallel to each other and perpendicular to the picture plane.The difference between
orthographic multiview drawings andan axonom
etric single-view drawin is simply t he orientation of
g
t heobject to t hepicture plane.
IsometricProjection
Isometric projection is an axonometric
projection of athree-dimensional subject
inclined to the picture plane in such away that
its three principal axes make equal angles with
t he picture plane and are equally foreshortened.
-
-1,
D etric Projection
im
-·- - - - - - - Dimetric projection isan axonometric projection
inwhich two of the principa l axes are equally
foreshortened and the thirdappears longer or
shorter than the other two.
i
T
rimetric P
rojection
---~r--------_... Trimetric projection is an axonometric
projection in which all three principal axes are
:
-l _
foreshortened at a different rate.
I
!
l
l
;
........
• Of these three. the most commonly used in
architectural drawing is isometric projection.
• All three axes receive equal emphasis.
• All axial lines-those parallel to the principal
axes- are drawn to true length at
the same scale.
AR C
HITECTURAL DRAWING S
YSTEMSI 29