Lecture 3Lecture 3

Applications of Computer Graphics

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Definition of Computer Graphics

R f t t d i Refers to any computer device or program that makes a computer capable of displaying and capable of displaying and manipulating pictures. (Webopedia)Computer graphics generally means Computer graphics generally means creation, storage and manipulation of models and images models and images

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Interactive Computer Graphics

First interactive graphics system, Sketchpad, by Ivan Sutherland

Note: using CRT monitor, light pen and function-key panel

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Interactive Computer Graphics

Touch Screen on PDA

HP I-PaqTM Wii by Nintendo

Virtual Sphere

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Desktop

Semi ImmersiveSe e s e

Fully Immersivee.G CAVE

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Games

•Virtual Reality: semi immersive (Wii), fully immersive (CAVE)

•On line game: Mech Quest, Penguin Club, Neo Pet, Dragon Fable

•Virtual World: Avatar (imaginary world)

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Computer Graphics: Doctored Photo

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Doctored photo by Reuters

Claimed Original Photo by Reuters

Doctored Photo: 2006

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Discovered Original Photo

Haptic Technology

The Haptic Workstation provides force feedback using an exoskeleton

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Computer Graphics: Eng Analysis

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Issue in computer graphics

I i di l f Image processing: medical, face recognitionP i ll l iProcessing: parallel processingRealism: particles in smokeReal time: collisionEffect on human by replacing y p gcomputer graphicsHologram

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g

What is the difference?

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Geometry-based vs imageGeometry-based applications store mathematical Geometry based applications store mathematical descriptions, or “models,” of geometric elements (lines, polygons, polyhedrons…) and associated attributes (e.g., color, material properties). Elements are primitive geometric shapes primitives for shortare primitive geometric shapes, primitives for short

Images created as pixel arrays (via sampling of geometry) for viewing, but not stored as part of geometry) for viewing, but not stored as part of model. Images of many different views are generated from same model

G t b d li ti th d l t h Geometry based applications cause the model to have physical properties and mathematical entities.Mathematical entities allow us to manipulate the model such as transformation and decompose complex model.

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p p

Decomposition of complex model

Decomposition TreeDecomposition Tree

Head

Nail

Body

Head

Shaft

Shaft(cylinder)

Point(cone)

Head(cylinder)

Body

d iti

Point

(cylinder) (cone)composition decomposition

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