1. Oblique Parallel
projection
CHANDAN GUPTA BHAGAT
067BCT512

2. A simple type of graphical
projection
 Used for producing pictorial, 2d images of 3d objects.

3. Oblique projection
 A parallel projection
 Projects a 3d image by the intersection of the parallel rays which is
known as projectors.
 Parallel lines of the source object produces a parallel lines in the
projected images.
 the projectors intersects the projection in oblique angle to produce
the projected image.
Parallel projection of the point(x,y,z) on the xy plane is (x+az,y+bz,0)

4. Types of parallel projection
 When a=b=0, the projection is said to be orthographic or orthogonal
 If not the projection is oblique

5. More about the parallel projection
 Crudest 3d drawing but easy to master.
 Oblique is not really 3d system but 2d view of an object with ‘forced
depth’.
 Oblique is rarely used as it is unconvincing to the eye.

6. Oblique peojection
 Angles displayed among the axes
 Foreshortening factors or scales are arbitrary
 Length along the x and y direction are preserved
 Length along the z axis are drawn at an angle using a reduction
factor

7. Cavalier projection
 Also known as high view point
 Length along the z axis remain unscaled
 Easy to draw
 Y axis is drawn diagonally making an angle of 30 or 45 degree with x
axis.
 X and z are perpendicular and length on these axes are 1:1 scaled

8. Cabinet projection
 Used by furniture industry
 One face of the object is parallel to the viewing plane
 Third axis is projected at angle 30 or 45 degree
 The projection length of the receding lines are half

9. Mathematical formula
A projected point has the following transformation formula
X = X + 0.5 * Z * cos()
Y = Y + 0.5 * Z * sin()
Z=0
 is the mentioned angle

10. sources
 Wikipedia.com