Oblique projection is defined as a pictorial projection in which projectors are parallel to each other and inclined to the plane of projection at any angle other than right angle. Orthographic and oblique projections. In orthographic projections (both multiview and axonometric) the projectors are parallel to each other and perpendicular to the plane of projection.
Trang 1Oblique Projections
Trang 2Oblique 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
Trang 3Oblique Projection Geometry
One face of object
parallel to projection
plane
Parallel projectors
make an oblique
angle with projection
plane
object
image
Trang 4Oblique Projection Angle ( α)
Angle of intersection of
projector with
projection plane
Determines type of
oblique projection
(Cavalier, Cabinet,
General)
Trang 5Classes of Oblique Projections
Type of
Oblique Projection Oblique
Angle (α )
Receding Axis Scale
General 45 ° < angle <
63.43 ° ½ < scale < 1
Trang 6Cabinet vs Cavalier
Cavalier
RA scale = 1
Cabinet
α = 63.43 °
RA scale = 1/2
Receding axis
Trang 7Receding Axis Angle
Determines relative emphasis of receding planes
Related to angle of rotation of projector
Trang 8Receding Axis Angle - 2
projector
normal
Trang 9Oblique Projection Generation
Trang 10Oblique Projections
C’est tout!