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.
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Oblique Projections
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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
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Oblique Projection Geometry
One face of object
parallel to projection
plane
Parallel projectors
make an oblique
angle with projection
plane
object
image
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Oblique Projection Angle (
Angle of intersection of
projector with
projection plane
Determines type of
oblique projection
(Cavalier, Cabinet,
General)
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Classes of Oblique
Projections
Type of
Angle ( )
Receding Axis Scale
General 45 < angle <
63.43 ½ < scale < 1
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Cabinet vs Cavalier
Cavalier
= 45
RA scale = 1
Cabinet
= 63.43
RA scale = 1/2
Receding axis
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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 ( )
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Receding Axis Angle 2 projector
normal
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Oblique Projection Generation
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Oblique Projections
C’est tout!