Orthographic projection is a method to represent the true size and shape of an object through multiple views by extending perpendiculars to a projection plane. It involves three main projection planes (horizontal, frontal, profile) and can convey up to six principal views of an object. Key principles include the spatial relationships of the views and the accuracy of lengths and areas when projected.

1. Orthographic
Projection

2. Definition
of
Orthographic Projection

3. Orthographic Projection
is the process of showing the true size and
shape of an object in two or more views by
extending perpendiculars from the object to the
plane.
The term Orthographic is derived from 2 Greek
words:
Orthos - means to write.
Graphos - means to draw.

4. Projection Plane or Plane of Projection
A projection plane, or plane of projection, is a type
of view in which graphical projections from an object
intersect.
Projection planes are used often in descriptive
geometry and graphical representation.
A picture plane in perspective drawing is a type of
projection plane.

5. Projection Plane or Plane of Projection

6. 3 Planes of Projection
1) Horizontal Plane- projected from the top view & will show
the top view of object.
2) Frontal Plane- projected from the front view & will show
the front view of object.
3) Profile Plane- projected from the side view (either side) &
will show the side view of object.

7. 3 Planes of Projection

8. 3 Principal Views:
1) Top View
2) Front View
3) Right Side View

9. 6 Principal Views:
1) Top View
2) Front View
3) Right Side View
4) Left Side View
5) Rear View
6) Bottom View

10. 6 PRINCIPAL VIEWS

11. Principles of Orthographic Projection:
1) The Top View is directly above the Front View.
2) The Side Views are in line horizontally with the Front View.
3) The depth or width of the Top View is equal to the depth or width of the Side Views.
4) A line parallel to the plane of projection will be projected as a line or in its true
length.
5) A line perpendicular to the plane of projection will be projected as a point.
6) A line inclined to the plane of projection will be projected shorter than its true length.

12. 7) A surface parallel to the plane of projection will be projected in its true size and shape.
8) A surface perpendicular to the plane of projection will be projected as a line.
9) A surface inclined to the plane of projection will be projected as a fore-shortened surface
or shorter than its true area.
10) No line can be projected on the picture plane longer than its true length.
11) No surface can be projected on the picture plane greater than its true length area.
Principles of Orthographic Projection:

13. REMEMBER: The Key to Succes
is the Education

14. QUIZ #4