1. 3D Projection Transformations

2. Contents 3D Projections -Perspective and Parallel Projections
-Orthographic and Oblique
-Isometric View
Oblique Projections

3. 3D Projections 3D projection is any method of mapping three-dimensional points to a two-dimensional plane.
Rays parallel to view plane
Rays converge on eye position
Perspective
Parallel
Orthographic
Oblique
Cavalier
Cabinet
Elevations
Axonometric
BACK
Isometric

4. Perspective and Parallel Projections
When the human eye views a scene, objects in the distance appear smaller than objects close by - this is known as perspective.
View plane
Parallel
Rays parallel to view plane
Perspective
Rays converge on eye position
BACK

5. 3D Projections Perspective Parallel Orthographic Oblique Elevations
Rays converge on eye position
Rays parallel
Perspective
Parallel
Rays at an angle to view plane
Rays perpendicular to view plane
Orthographic
Oblique
Elevations
Axonometric
Cavalier
Cabinet
Isometric
BACK

6. Parallel Projections:Orthographic and Oblique
View plane
Oblique
Rays at an angle to view plane
Orthographic
Rays perpendicular to view plane
BACK

7. 3D Projections Parallel Perspective Orthographic Oblique
Rays parallel
Rays converge on eye position
Parallel
Perspective
Rays at angle to view plane
Rays perpendicular to view plane
Orthographic
Oblique
View plane aligned with principal axes
View plane not aligned with principal axes
Cavalier
Cabinet
Elevations
Axonometric
Dimetric
Isometric
Trimetric
BACK

8. Isometric View
In isometric view, the three principal axes of the object intersect the view plane at equal distance. Therefore, when projected, they are 120o apart.
BACK

9. 3D Projections Parallel Perspective Orthographic Oblique Cavalier
Rays parallel
Rays converge on eye position
Rays at angle to view plane
Parallel
Perspective
Rays perpendicular to view plane
Orthographic
Oblique
Cavalier
Cabinet
Elevations
Axonometric
Isometric
BACK

10. Oblique projections a a 1 1 1
Projection lines are at an angle to the view plane i.e. Projection lines are not perpendicular to view plane. 1 a 2 a
Cavalier :Here direction of projection makes 45 degrees angle with view plane and the projection of a line perpendicular to view plane has same length as the line. 1 1
Cabinet :Here direction of projection makes 63.4 degrees angle with view plane and the projection and lines perpendicular to viewing surface are projected at one half their actual length. 1
1/2 1
BACK 1

11. Thanks !!!