Reference Book
ORTHOGRAPHIC PROJECTION
Orthographic projection is one method of projection used in engineering
drawing in which the objects are projected on imaginary planes. This means
we make the object become 2D. The difference between Orthographic
Projection and any other drawing method is that we use several 2D views of
the object instead of a single view.
In orthographic projection the object is placed at infinite distance from the
observer. The image formed on the pictureplane is orthographic projection.
The word orthographic means to draw at right angles.Basics of Orthographic Projection
Orthographic Projection involves us seeing an object in 2D. To do this we
need to look at 90 degrees to the face of an object. The planes of projection are
extended beyond the line of intersection to form four quadrants. The position
of objects in any one these four quadrants are as follows- First horizontal plane(HP) in front of vertical plane(VP)
- Second quadrant-Above HP and behind VP
- Third quadrant-Below HP and behind VP
- Fourth quadrant; Below HP and in front of VP
ORTHOGRAPHIC VIEWS
Orthographic views are obtained from orthographic projection. The front, top
and side views are called as orthographic views. In orthographic projection,
the picture planes are called as planes of projection and the perpendicular line
are called as project lines or projectors. When we draw an Orthographic view
of the front of an object it is called ELEVATION. When we draw an
Orthographic view of the top of an object it is called PLAN. When we draw an
Orthographic view of one side of an object it is called an END ELEVATION.
Side view (EE) Front view(E)
Top view (P)