CADCAMCAE Systems

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CAD/CAM/CAE Systems

• GE393
• Computer Aided Design, Analysis Prototyping

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Product Development

• To compete, new products must continuously
• Improve quality
• Reduce cost
• Shorten lead time

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Product Modeling

• Design model
• Actual design geometry
• Analysis model
• Abstraction of the geometric model
• Eliminate details
• Dimensional reduction (3D 2D, 1D)
• Employ symmetry

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CAD, CAE, and CAM

• Computer-aided design (CAD)
• Define design geometry
• Computer-aided engineering (CAE)
• Analyze CAD geometry
• Computer-aided manufacture (CAM)
• Plan, manage, control manufacturing operations

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Graphics Device Hardware

• Display processing unit
• Display device (monitor)
• Input devices (mouse, keyboard, etc)

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Kinds of Graphics Devices

• Vector-refresh
• Line drawing device
• High resolution, straight lines
• Random refresh
• Raster-refresh
• Point plotting device
• Aliasing problems
• Regular, repetitive refresh
• High performance to cost ratio

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Vector-Refresh

• 3 Components
• Display processing unit
• Display buffer
• CRT
• Display buffer
• Hardware (memory)
• Display list
• Software (commands)
• Refresh (redrawing) time
• Image repeatedly drawn
• lt 30 Hz, flicker

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Raster Graphics

• Screen image represented by an array of dots
  (pixels)
• Raster image stored in frame buffer a portion
  of memory
• Dot size determines resolution
• Refresh required

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Raster Graphics Display Processor

• Generates and stores raster image in frame buffer
• Reads frame buffer contents and casts electron
  beams onto display device

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Raster Scanning

• Scan lines
• Refresh time
• constant
• 30 Hz (TV)
• 60 Hz (high end)

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Frame Buffer Bit Planes (Color)

• 1-bit plane (bitmap 1 bit per pixel)
• Black and white
• 3-bit planes
• 8 (23) colors
• 8-bit planes
• 256 (28) colors
• 24-bit planes
• 16,777,216 ((28)3 or 224) colors

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3-Bit Plane Color
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3-Bit Plane Color Table
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24-Bit Plane Color
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CAD/CAM/CAE Systems

• Computer Aided Design, Analysis Prototyping