Object representation Glass box concept Line convention Orthographic projection of point , Multiview projection... OBJECT REPRESENTATION Axonometric projection Multiview projection... PR
Trang 1Chapter 3
Orthographic
Projection
Trang 2Object representation
Glass box concept
Line convention
Orthographic projection of point ,
Multiview projection
Trang 3OBJECT REPRESENTATION
Axonometric projection
Multiview projection
Trang 51 Revolve the object with respect
to observer
TO OBTAIN MULTIVIEW REPRESENTATION OF AN OBJECT
object.
Trang 6REVOLVE THE OBJECT
Front
view
Right side view Top view
Trang 7OBSERVER MOVE AROUND
Front view Right side
view Top view
Trang 8THE GLASS BOX CONCEPT
Bottom view Left side view
Rear view
Trang 9Height Width
Trang 10Orthographic
Projection
of Object Features
Trang 11OBJECT FEATURES
Edges are lines that represent the boundary
between two faces
Corners Represent the intersection of two or
Trang 12Surfaces are areas that are bounded by edges
or limiting element
Limiting
element is a line that represents the last visiblepart of the curve surface.
Surface Surface Surface
Limit
Limit
OBJECT FEATURES
Trang 14Equal length
PROJECTION OF LINE
Trang 15PROJECTION OF LINE
Trang 16Foreshortened Foreshortened
Trang 17Edge Edge
Trang 18BTC
Trang 19BTC
Trang 21s
sPROJECTION OF OBJECT
Trang 22PROJECTION OF OBJECT
Trang 23Line Convention
Trang 25PRECEDENCE OF LINE
Visible line
Visible line
Order of
importance
Hidden line
Hidden line
Center line
Center line
Trang 26HIDDEN LINE PRACTICE
Hidden line should join a visible line, except it
extended from the visible line
Correct
No !
Join
Leave space
Trang 27Correct No !
Hidden line should join a visible line, except itextended from the visible line
Leave space
Leave space
HIDDEN LINE PRACTICE
Trang 28Hidden line should intersect to form L and T
Trang 29Hidden arcs should start on a center line.
HIDDEN LINE PRACTICE
Trang 30CENTER LINE PRACTICE
In 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
Trang 31Leave the gap when centerline forms a
continuation with a visible or hidden line
Leave space
Leave space
Leave space