ORTHOGRAPHIC PROJECTION

1
ORTHOGRAPHIC PROJECTION

• Orthographic projection is the organization of
  multiple views of an object. In order to fully
  and accurately represent the object, more than
  one view is typically required.

2
Principal Views of an Object

• All orthographic projections are composed of six
  sides or planes of projection. All six views are
  not necessary to describe the object.

3
Perpendicular Projection to Each Face

• The lines of the object are projected
  perpendicular to the face to create each view.

4
Each View Provides Two Measurements

• a. Top and Bottom views show DEPTH and WIDTH.
• b. Left and Right views show HEIGHT and DEPTH
• c. Front and Rear views show HEIGHT and WIDTH.

5
Measurement Transfer Between Views

• The mitre line (drawn at a 45 angle) is used to
  transfer depth measurements between the top and
  right side (or left side) views.

6
Normal Plane

• Normal Planes will appear as an edge in two views
  and a true sized plan in the remaining view when
  using three views such as a top, front and right
  side.

7
Inclined Plane

• Inclined Planes will appear as an edge view in
  only one of the three views. The inclined plane
  will appear as a rectangular surface in the other
  two views.

8
Oblique Planes

• Oblique Planes will not appear as an edge view
  in any of the six views since they are not
  parallel or perpendicular to the projection
  planes.
• They always appear as a plane and have the same
  number of corners in each of the six views.

9
Curved Surfaces

• A cylinder will appear as a circle in one view
  and a rectangular shape the other two views.

10
Axis and Center Lines

• The axis appears where the cylinder appears
  rectangular.
• Center marks are used to identify the center of
  the cylinder where it appears circular.