Orthographic Projection Basics
description
Transcript of Orthographic Projection Basics
• Engineering 1182
College of EngineeringEngineering Education Innovation Center
Orthographic Projection Basics
Chapter 10 of Text
• Engineering 1182
Objectives
• Discuss the principles of orthogonal projection
• Show how and why orthogonal projection is used to create multiple views of an object for formal engineering drawings
• Create a multiview drawing from a 3-D object
Note: The terms orthogonal and orthographic are used to refer to the same drawing type.
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Why Orthographic Drawings? • The best way to communicate what an object
looks like is to show someone an image. • Isometric sketches distort the features of an
object and may lead to misinterpretation.• Objects must be represented in a way that
prevents misinterpretation. • Multiview drawings show how an object looks
from multiple angles.• Multiviews help to prevent any mis-
communications that may happen when looking at only isometric pictorials.
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Orthographic Projections
• Orthographic projections are another way of representing a 3D object in 2D space.
• In an orthographic projection, the object is projected perpendicularly onto a viewing plane.
• By using a multiview drawing, we can eliminate misinterpretations that isometric views alone allow.
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Orthographic Projections• When drawing an
orthographic multiview, it sometimes helps to visualize the object inside of a glass box.
• Imagine that the object is projected on to each surface of the glass box.
• The box is then unfolded to form the multiview drawing.
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How Many Views Do We Need?• Just projecting one view of a surface isn’t
enough to completely describe the object
This single view can be interpreted in at least 6 different ways!
• To completely describe the object multiple views are shown.
• Generally, the front, top, and right side are sufficient to fully represent an object.
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Orthographic Projection• Use your snap cubes to build the following
object. • Look at if from the front, right, and top
sides.
Top
221
Front RightCLICK
Note: These are the 3 views associated with the object you just built.
Top
Front Right
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Orthographic Projections• Typically, the front, top, and right side
views are sufficient to fully describe an object.
Top
Front Right
Right
Top
Front
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View Alignments • In orthographic
projections, the views are aligned such that each point on the object is lined up with itself all three views.
• Each view shows two dimensions– Top: width and depth– Front: height and width– Right side: height and depth
A
A A
A
B
B
B
B
Hei
ght H
eight
Width
Width
Dep
th
Depth
Width
Height
Depth
CLICK
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Orthographic Projections
• Use this time and your snap cubes to practice building objects and sketching orthographic projections.
• In class assignment