CIVIL ENGINEERING DRAWING

1. PICTORIAL
Sketching /
ISOMETRIC
Sketching
BY SAFIULLAH 13CE07 SCET WAH CANTT
CONTT;03479164097

2. Introduction
Orthographic view shows only two dimensions in
any particular view. This makes it difficult to
interpret them and only technically trained person
can interpret the meaning of these orthographic
views. A non-technical person Can not imagine the
shape of the object from orthographic projections.
Whereas, pictorial projections can be easily
understood even by persons Without any technical
training because such views show all the three
Dimensions Of an object in the same view.

3. But pictorial view does not show the true shape
and size of any principal surface of An object and
it does not show the hidden portions.
Pictorial projections are easy to imagine so these
are used in sales literature.

4.  Principle of Projection :
If straight lines are drawn from various points
of an object to meet a plane then it is said that
object is Projected on that plane.
These straight lines from the object to the
plane are called projectors.
The figure formed by joining the points at
which the projectors meet the plane is called
Projection of that object.

5. Types of Projection:
I) Orthographic Projection
II) Pictorial Projection
Pictorial Projection :
The projection in which the length , height
And depth are shown in one view is
called Pictorial Projection.

6. Isometric Sketching / Isometric Projection :
An isometric sketch, although a pictorial or three
Dimensional drawing, is not drawn as an object
appears to the eye. It is made according to the
actual dimensions as for as possible. For this
reason it often looks unnatural. However, because
It can be dimensioned and it is easy to draw, an
Isomeric sketch is preferred in engineering works.
The projection is obtained on a plane which is
equally inclined to all the three principal planes.

7. When a cube is kept in particular position then it
gives isometric axes, isometric lines and isometric
planes.
Particular position : When cube is resting on H.P.
on corner G and diagonal EC is Perpendicular to
V.P. A
C
D
G
H
E
30o 30o
B
F
M N Base Line

8. Isometric Axes :
The three lines CB,CD and CG meeting at the point
C and making angle of 120 degree with each other
are called isometric axes.
Isometric lines:
The lines parallel to isometric axes are called
isometric lines.
Isometric planes:
The planes represented by faces of cube are called
isometric planes.
Similarly any planes parallel to these planes are also
called isometric planes.

9. Isometric drawing or isometric view:
The pictorial view drawn with true scale is called
Isometric drawing or isometric view.
Isometric projection:
The pictorial view drawn with the use of isometric
scale is called Isometric projection.

10. F.V.
T.V.
L.H.S.V.
X

11. F.V.
T.V.
C1
C1’
C2’
C2

12. 4 3
a b
e
d
c
2
1
3
2
4
1
a
b
e
d
c
3’
2’
4’
1’
a’
b’
e’
d’
c’

13. T.V.
F.V.
X
a’
c’
M1
C3’
M2
N1
N2
C3
C4 C1
C2
b’
C4’ d’
C2’

14. 15
ISOMETRIC
35
b
40
1
2
a
3
d
X
c
A
B
20
VIEW
b c d
1 2
15
30
3
NOTE:- IN R.H.S.MISSED VIEW, THE AREAS, A & B ARE
SEEN AND IS DRAWN IN ITS CORROSPONDING
SPACE
20
15
55
T.V.
15 20
60
55
F.V.
a