Orthographic Writing

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Chapter 3 Orthographic Projection
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TOPICS
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OBJECT REPRESENTATION
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MULTIVIEW PROJECTION
Three principle dimensions of an object
can be presented only two in each view.
Adjacent view(s) is needed tofulfill the
size description.
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TO OBTAIN MULTIVIEW REPRESENTATION OF AN OBJECT

• Revolve the object with respect
• to observer.

• The observer move around the
• object.

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REVOLVE THE OBJECT
Top view
Right side view
Front view
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OBSERVER MOVE AROUND
Top view
Front view
Right side view
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THE GLASS BOX CONCEPT
Rear view
Left side view
Bottom view
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(No Transcript)
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MULTIVIEW PROJECTION
Click on the picture to play video
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MULTIVIEW PROJECTION
Click on the picture to play video
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MULTIVIEW PROJECTION
Click on the picture to play video
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MULTIVIEW PROJECTION
Click on the picture to play video
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Orthographic Projection of Object Features
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OBJECT FEATURES
are lines that represent the boundarybetween two
faces.
Edges
Represent the intersection of two ormore edges.
Corners
Edge
Edge
No edge
Corner
No corner
No corner
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OBJECT FEATURES
are areas that are bounded by edges or limiting
element.
Surfaces
is a line that represents the last visible part
of the curve surface.
Limitingelement
Limit
Limit
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PROJECTION OF POINT(S)
BT
BT
AT
AT
B
A
BR
AF
BF
AR
BR
AF
BF
AR
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PROJECTION OF LINE
True length
BT
AT
BT
Equal length
AT
B
A
BR
AF
BF
AF
BF
AR
BR
AR
Point
True length
NORMAL LINE
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PROJECTION OF LINE
True length
BT
AT
BT
Equal length
AT
B
A
A
AF
BR
AF
BF
BF
AR
BR
AR
Foreshortened
Foreshortened
INCLINED LINE
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PROJECTION OF LINE
Foreshortened
BT
AT
BT
B
Equal length
BR
BF
AT
B
A
BF
BR
AF
A
AF
AR
AR
Foreshortened
Foreshortened
OBLIQUED LINE
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PROJECTION OF PLANE
True size
CT
BT
CT
AT
Equal length
BT
AT
C
B
CR
A
BF
AF,CF
BF
AF,CF
CR
AR,BR
AR,BR
Edge
Edge
NORMAL PLANE
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PROJECTION OF PLANE
Foreshortened
CT
BT
CT
AT
C
Equal length
BT
AT
CR
CF
C
B
CF
CR
A
BF
AF
AR,BR
BF
AF
AR,BR
Edge
Foreshortened
INCLINED PLANE
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PROJECTION OF PLANE
Foreshortened
CT
BT
CT
AT
C
Equal length
B
CR
BT
AT
BF
CF
C
B
CF
BR
BR
CR
BF
A
AF
AR
AF
AR
Foreshortened
Foreshortened
OBLIQUED PLANE
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PROJECTION OF OBJECT
The views are obtained by projecting all object
features to the picture plane.
You have to project the remaining surfaces which
are invisible too !
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PROJECTION OF OBJECT
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PROJECTION OF OBJECT
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Line Convention
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LINE CONVENTION
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PRECEDENCE OF LINE
Visible line
Order of importance
Hidden line
Center line
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HIDDEN LINE PRACTICE
Leave space
Correct
Join
No !
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HIDDEN LINE PRACTICE
Leave space
Leave space
Correct
No !
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HIDDEN LINE PRACTICE
Correct
L
T
No !
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HIDDEN LINE PRACTICE
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CENTER LINE PRACTICE
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CENTER LINE PRACTICE