Lecture Autodesk inventor Oblique projections

Oblique Projections


Oblique Sketches
Show exact size and shape of one face of an
object
Object face with most detail parallel to view
plane
Relatively easy to draw

Oblique Axes

Oblique Sketch


Oblique Projection Geometry
object

One face of object
parallel to projection
plane
Parallel projectors
make an oblique
angle with projection
plane

image


Oblique Projection Angle (α)
Angle of intersection of

projector with
projection plane
Determines type of
oblique projection
(Cavalier, Cabinet,
General)


Classes of Oblique Projections
Type of
Oblique

Receding
Axis Scale

Cavalier

Oblique
Projection
Angle (α)
45°

Cabinet

63.43°

1/2

General

1

45° < angle < ½ < scale < 1
63.43°


Cabinet vs Cavalier

Cabinet

Cavalier

α = 63.43°

α = 45°

RA scale = 1/2

RA scale = 1

Receding axis


Receding Axis Angle
Normally chosen to be 30 °, 45 °, or 60 °
Determines relative emphasis of receding
planes
Related to angle of rotation of projector
about the projection plane normal (β)

Receding Axis Angle - 2

projector

normal


Oblique Projection Generation


Oblique Projections

C’est tout!