Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to...
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Transcript of Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to...
![Page 1: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/1.jpg)
Graphics-1
Gentle Introduction to Computer Graphics
• Based on:– David Brogan’s “Introduction to Computer
Graphics” Course Slides, University of Virginia
– Jack van Wijk’s “Computer Graphics” Course Slides, University of Eindhoven.
![Page 2: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/2.jpg)
Graphics-2
Outline
• Graphics Applications
• What is Computer Graphics
• Representations in Graphics
• Supporting Disciplines
• Introduction to 2d Modeling Transformations
• Matrix Representations
• Linear Transformations
![Page 3: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/3.jpg)
Graphics-3
Graphics Applications
• Entertainment: Cinema
Pixar: Monster’s Inc.
A Bug’s Life (Pixar)
![Page 4: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/4.jpg)
Graphics-4
Graphics Applications
• Medical Visualization
MIT: Image-Guided Surgery Project
Th
e V
isib
le H
um
an
Pro
jec
t
![Page 5: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/5.jpg)
Graphics-5
Graphics Applications
• Everyday use
![Page 6: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/6.jpg)
Graphics-6
Graphics Applications
• Scientific Visualization
![Page 7: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/7.jpg)
Graphics-7
Graphics Applications
• Computer Aided Design (CAD)
![Page 8: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/8.jpg)
Graphics-8
Graphics Applications
• Training
Designing Effective Step-By-Step Assembly Instructions (Maneesh Agrawala et. al)
![Page 9: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/9.jpg)
Graphics-9
Graphics Applications
• Games
GT Racer 3
Polyphony Digital: Gran Turismo 3, A Spec
![Page 10: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/10.jpg)
Graphics-10
Graphics Applications
• Games
Circus Atari (Atari)
![Page 11: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/11.jpg)
Graphics-11
What is Computer Graphics?
• Computer graphics: generating 2D images of a 3D world represented in a computer.
• Main tasks:– modeling: (shape) creating and representing
the geometry of objects in the 3D world– rendering: (light, perspective) generating 2D
images of the objects– animation: (movement) describing how
objects change in time
![Page 12: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/12.jpg)
Graphics-12
What is Computer Graphics?
ImageMath. ModelImage Analysis(pattern recognition)
Image Synthesis(Rendering)
Modeling Image processing
![Page 13: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/13.jpg)
Graphics-13
Representations in graphics
Vector Graphics
• Image is represented by continuous geometric objects: lines, curves, etc.
Raster Graphics
• Image is represented as a rectangular grid of colored pixels
![Page 14: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/14.jpg)
Graphics-14
Vector graphics
• Graphics objects: geometry + color
• Relatively low processing time– in terms of the number of graphic objects
• Geometric transformation possible without loss of information (zoom, rotate, …)
• Examples: PowerPoint, CorelDraw, ...
![Page 15: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/15.jpg)
Graphics-15
Raster graphics
• Generic
• Image processing techniques
• Geometric Transformation: loss of information
• Relatively high processing time– in terms of the number of pixels
• Realistic images, textures, ...
• Examples: Paint, PhotoShop, ...
![Page 16: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/16.jpg)
Graphics-16
Supporting Disciplines
• Computer science (algorithms, data structures, software engineering, …)
• Mathematics (geometry, numerical, …)
• Physics (Optics, mechanics, …)
• Psychology (Colour, perception)
• Art and design
![Page 17: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/17.jpg)
Graphics-17
Introduction to Modeling Transformations
• Specify transformations for objects – Allows definitions of objects in own
coordinate systems– Allows use of object definition multiple
times in a scene
![Page 18: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/18.jpg)
Graphics-18
2D Modeling Transformations
ScaleRotate
Translate
ScaleTranslate
x
y
World Coordinates
ModelingCoordinates
![Page 19: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/19.jpg)
Graphics-19
Scaling
• Scaling a coordinate means multiplying each of its components by a scalar
• Uniform scaling means this scalar is the same for all components:
2
![Page 20: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/20.jpg)
Graphics-20
• Non-uniform scaling: different scalars per component:
• How can we represent this in matrix form?
Scaling
X 2,Y 0.5
![Page 21: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/21.jpg)
Graphics-21
Scaling
• Scaling operation:
• Or, in matrix form:
by
ax
y
x
'
'
y
x
b
a
y
x
0
0
'
'
scaling matrix
![Page 22: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/22.jpg)
Graphics-22
2-D Rotation
(x, y)
(x’, y’)
x’ = x cos() - y sin()y’ = x sin() + y cos()
![Page 23: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/23.jpg)
Graphics-23
2-D Rotation
• This is easy to capture in matrix form:
• Even though sin() and cos() are nonlinear functions of ,– x’ is a linear combination of x and y– y’ is a linear combination of x and y
y
x
y
x
cossin
sincos
'
'
![Page 24: Graphics-1 Gentle Introduction to Computer Graphics Based on: –David Brogan’s “Introduction to Computer Graphics” Course Slides, University of Virginia.](https://reader034.fdocuments.in/reader034/viewer/2022042702/56649d385503460f94a116bb/html5/thumbnails/24.jpg)
Graphics-24
2-D Translation
(x, y)
(x’, y’)
x’ = x + txy’ = y + ty
tx
ty