Visualization and Graphics Introduction

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Visualization and Graphics Introduction

• Drafting, Sketching Dimensioning

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Objectives

• Understanding graphics as a communication tool
• Technical sketching
• Freehand
• Instrument
• Computer
• Projections
• Orthographic
• Pictorial

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Visualization

• Visualization is often used as a mode of
  communication between engineers
• Sketches, tables, graphs, computer generated
  drawings, blueprints are various ways in which
  engineers communicate via visual mediums

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How Would You Describe This?

• In teams of two, describe using only words
• How effective is this approach?

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Three Basic Types of Technical Drawings

• Freehand sketches
• Instrument drawings
• Computer drawings

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Introduction to Projections

• Present 3-D objects with 2-D media
• Two Basic Categories
• Orthographic Pictorial

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Projections Four Basic Types
Note Isometric is a special case of Axonometric
Axonometric
Pictorials
Oblique
Perspective
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Types of Axonometrics
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Pictorial Drawings

• Shows an object like you would see in a
  photograph
• Give a three dimensional view of a room or
  structure
• Three common types
• Isometric (Axonometric)
• Oblique
• Perspective

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Pictorial Sketch of Kitchen
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Review Questions 1-2

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Isometric Drawings

• The most common pictorials
• Constructed with the two faces 30 degrees above
  the horizontal
• The axes are 120 degrees between each axis
• Lines that are horizontal are drawn at 30 degrees
• Vertical lines remain vertical

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Isometric Projection
?CUBE?

• Isometric means equal measure
• All planes are equally or proportionately
  shortened and tilted
• All the major axes (X, Y, Z) are 120 degrees
  apart

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• Making an Isometric Sketch
• Defining Axis

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Isometric of a Cube
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Isometric Dimensioning

• Dimension lines are parallel to the isometric
  axes
• Extension lines are extended in line with these
  axes

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Oblique Drawings

• The front view is draw like it would be using
  orthographic projection
• The front view shows all features with true shape
  and size
• The top and side view are then projected back
  from the front view
• Views can be at any angle
• 15, 30 or 45 degrees are common

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Oblique Drawing
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Oblique Drawings Continued

• Useful when the front contains more details and
  features than the side view
• A mental image can be created more quickly than
  with orthographic alone
• Two types of oblique drawings
• cavalier
• cabinet

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Review Questions 3-5
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Cavalier Oblique

• The entire drawing uses the same scale
• Sometimes creates a distorted appearance

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Which is the cube ?
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Were you right?
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Cavalier Oblique

• Front view true size
• Receding Axis Angle (Normally 30, 45 or 60) is
  Variable
• Depth dimension (receding axis) true size

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Cabinet Oblique

• Front view true size
• Receding Axis Angle (Normally 30, 45 or 60) is
  Variable
• Depth dimension (receding axis) half size

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Cavalier Oblique Drawing
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Cabinet Oblique

• Measurements on the receding axes are reduced by
  half
• More visually realistic representation
• Often used for drawing cabinets

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Cabinet Oblique Drawing
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Side by Side Comparison
Cavalier Oblique
Cabinet Oblique
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Review Questions 6-8
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Perspective Drawings

• The most realistic of all pictorial drawings
• Receding lines in the drawing meet at a
  vanishing point instead of being parallel
• Eliminates distortion at the back part of
  pictorial drawings
• Two types
• parallel (one-point) perspective
• angular (two point) perspective

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Perspective Drawing
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Parallel Perspective (One Point)

• One face of the object is shown as the front view
• Lines parallel to the front view remain parallel
• Lines that are perpendicular to the front view
  converge at a SINGLE VANISHING POINT

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Angular Perspective (Two-Point)

• Similar to isometric drawings
• One edge of the object is place in front
• The two faces that meet at this edge recede to
  DIFFERENT VANISHING POINTS
• All lines parallel to each face go to the
  different vanishing points

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Angular Perspective Drawing
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Types of Perspectives
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Horizon Below Object
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Exploded Pictorial Drawings

• Used to show relative position of parts or
  construction details
• Used to clarify assembly sequence
• Common in appliance and cabinetry service manuals

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Exploded Pictorial Drawing