Lecture Autodesk inventor Multiview projections 1 Glass box theory. After completing this chapter, you will be able to Explain orthographic and multiview projection; identify frontal, horizontal, and profile planes; identify the six principal views and t

Multiview Projections 1
Glass Box Theory


Some Characteristics
Parallel projectors
Projectors normal
to projection plane
Object positioned
with one face
parallel to
projection plane

PP
Projectors

PEB

Only one face visible  need more than one view
to describe object


Glass Box Theory - 1
Mutually perpendicular
projection planes (sides of
glass box)
Position object inside glass
box. PEB orthogonal to sides
of glass box
Six principal views
(front/back, top/bottom,

left/right)
Frontal (F), Horizontal (H),
Profile (P) projection planes
Object dimensions (width,
height, depth)
Hinges – fold lines (H/F, F/P)


Glass Box Theory - 2
Images projected onto
the projection planes


Glass Box Theory - 3
Sides of glass box
hinged (H/F, F/P) so
that when opened …


Glass Box Theory - 4
the views are aligned
as shown here:


Glass Box Theory - 5


View Alignment/View Placement

Arrangement of Views
Top and Front are
vertically aligned,
share width dimension
Front and Right are
horizontally in line,
share height dimension
Top and right are not
aligned, share depth
dimension


Transfer of Depth
Every point or
feature in one view
must be aligned on
a parallel projector
in an adjacent /
related view


Line Conventions
Alphabet of lines
Visible lines – used to represent visible
edges on an part
Center Lines – used to identify centers
of circles and axes of cylinders (holes).
Also used to identify symmetry and to
show path of motion

Multiview Drawing of a Cylinder
Centerlines only
cross in circular
view
Extend center
lines about 5mm
past object edge

edge

NOTE: Limiting elements refer to the extents of a
curved surface. In engineering graphics lines are
use to represent limiting elements, just as they
are used to represent edges.

limiting
element


Hidden Lines
Hidden lines are used to show hidden features
(e.g., edges, limiting elements, etc.) on an object
Holes – locate
limiting elements
Surfaces – locate
edge view of a
surface
Change of planes
– locate position

of a change of
plane or a corner


Multiview Projections 1

This is the end!