orthographic writing - الصفحات الشخصية | الجامعة...
TRANSCRIPT
TOPICS
Object representation
Glass box concept
Line convention
Orthographic projection of point,line, plane, surface and object.
Multiview projection
MULTIVIEW PROJECTIONThree principle dimensionsof an object …
Width Depth
Height
Width
Hei
ght
Depth
Dep
th
… can be presented onlytwo in each view.
Adjacent view(s)is needed tofulfill the sizedescription.
1. Revolve the object with respect to observer.
TO OBTAIN MULTIVIEW REPRESENTATION OF AN OBJECT
2. The observer move around the object.
OBJECT FEATURESEdges are lines that represent the boundary
between two faces.
Corners Represent the intersection of two ormore edges.
Edge
Corner
Edge No edge
No corner No corner
Surfaces are areas that are bounded by edgesor limiting element.
Limitingelement
is a line that represents the last visiblepart of the curve surface.
Surface Surface Surface
LimitLimit
OBJECT FEATURES
A
B
AF BF BRAR
AT
BT
BR
AR
AF BF
AT
BT
True length
NORMAL LINETrue lengthPoint
Equallength
PROJECTION OF LINE
A B
AF BF BRAR
AT
BT
INCLINED LINEForeshortened
BR
AR
AF
BF
Foreshortened
AT
BT
True length
A
Equallength
PROJECTION OF LINE
A B
AF
BF BR
AR
AT
BT
OBLIQUED LINE
A
Equallength
B
ForeshortenedForeshortened
Foreshortened
BR
AR
AF
BF
AT
BT
PROJECTION OF LINE
B C
A
PROJECTION OF PLANE
BF AF,CF CRAR,BR
AT
CT
NORMAL PLANE
Equallength
EdgeEdge
True size
CR
AR,BR
AF,CF
BF
AT
BT
CT
BT
B C
BF AF
CR
AR,BR
AT
CT
INCLINED PLANE
A
Equallength
BT
C
CF
Edge
CR
AR,BR
Foreshortened
BT
CT
AT
AF
CF
Foreshortened
BF
PROJECTION OF PLANE
BC
BF
AF
CR
AR
AT
CT
OBLIQUED PLANE
A
Equallength
BT
C
CF
B
BR
Foreshortened
CR
AR
BR
AF
BF CF
Foreshortened
AT
BT
CT
Foreshortened
PROJECTION OF PLANE
PROJECTION OF OBJECTThe views are obtained by projecting all object features to the picture plane.
You have to project the remaining surfaces which areinvisible too !
HIDDEN LINE PRACTICEHidden line should join a visible line, except itextended from the visible line.
Correct
No !
Join
Leavespace
Correct No !
Hidden line should join a visible line, except itextended from the visible line.
Leavespace
Leavespace
HIDDEN LINE PRACTICE
CENTER LINE PRACTICEIn circular view, short dash should cross at the intersections of center line.
For small hole, center line is presented as thin continuous line.
Center line should not extend between views.
Leave space Leave space