computer graphics - university of oulujiechen/course/lecture1/cg_instruction-c...• computer...

C O M P U T E R G R A P H I C S

Guoying Zhao 1 / 58


Guoying Zhao 1 / 58

Computer Graphics

Introduction I


Guoying Zhao 2 / 58


Guoying Zhao 2 / 58

A Survey of Computer Graphics

• What is computer graphics?• Interactive computer graphics• The history of computer graphics• Computer graphics applications• Device


Guoying Zhao 3 / 58


Guoying Zhao 3 / 58

What is Computer Graphics?

• Some possible definitions:– Approaches, Methods, Technics and Tools for virtual

world visualization– Generating 2D images of a 3D world represented in

computer• Main tasks

– Modeling: construct the 3D model of the scene– Rendering: compute the color of each pixel– Animation


Guoying Zhao 4 / 58

What is Computer Graphics? (1/2)• Computer graphics generally means creation, storage and manipulation of

models and images• Such models come from diverse and expanding set of fields including

physical, mathematical, artistic, biological, and even conceptual (abstract) structures

Frame from animation by William Latham, shown at SIGGRAPH 1992. Latham uses rules that govern patterns of natural forms to create his artwork.


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• William Fetter coined term “computer graphics” in 1960 to describe new design methods he was pursuing at Boeing

• Created a series of widely reproduced images on pen plotter exploring cockpit design, using 3D model of human body.

“Perhaps the best way to define computer graphics is to find out what it is not. It is not a machine. It is not a computer, nor a group of computer programs. It is not the know-how of a graphic designer, a programmer, a writer, a motion picture specialist, or a reproduction specialist.

Computer graphics is all these – a consciously managed and documented technology directed towardcommunicating information accurately and descriptively.”

Computer Graphics, by William A. Fetter, 1966

What is Computer Graphics? (2/2)


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What is Interactive Computer Graphics? (1/3)

• User controls contents, structure, and appearance of objects and their displayed images via rapid visual feedback

• Basic components of an interactive graphics system– input (e.g., mouse, tablet and stylus, force feedback device, scanner, live video streams…)– processing (and storage)– display/output (e.g., screen, paper-based printer, video recorder, non-linear editor…)

• First truly interactive graphics system, Sketchpad, pioneered at MIT by Ivan Sutherland for his 1963 Ph.D. thesis

Sketchpad in 1963. Note use of a CRT monitor, light pen and function-key panel.


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• Before Sketchpad, output via plotters/printers, input via keypunch, both in batch

Card punching (left). IBM 704 (right) took up a whole room and was capable of about 4,000 arithmetic operations/second.

Cool facts: Whirlwind, built in early 50’s at MIT, cost $4.5 million and could perform 40,000 additions/second. Mac 512K, list price $3,195 in 1984, could do 500,000.

Batch (1950s – now)

What is Interactive Computer Graphics? (2/3)


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Guoying Zhao 8 / 58

The Graphics Process


Guoying Zhao 9 / 58


Guoying Zhao 9 / 58

Modeling

Modeling with Maya


Guoying Zhao 10 / 58



Modeling

Modeling from image





Modeling

The tree model(a) without leaves (b) with leaves





Modeling---Geometry Processing





Rendering

Indirect diffusion Caustic effect





Rendering

“A Rapid Hierarchical Rendering Technique for Translucent Materials”. Jensen, Siggraph’2002





Rendering





Questions

• Graphics Vs. Image ?- geometric elements and attributes

- pixel arrays

• Computer Graphics Vs. Image Processing– CG : 3D Models -> rendering -> images– I. P : 2D images -> analysis -> models(other

information, special effects...)



The History of Computer Graphics

Pioneer: Ivan Sutherland1963: Sutherland’s PhD Thesis：“Sketchpad: A Man-machine Graphical Communications System.”, MIT,1963

First time used “Computer Graphics”. CG started to be a novel and independent scientific branch.



Pioneer：Ivan Sutherland

• First truly interactive graphics system, Sketchpad, pioneered at MIT by Ivan Sutherland for his 1963 Ph.D. thesis

Sketchpad in 1963. Note use of a CRT monitor, light pen and function-key panel.






• Poineer: Ivan Sutherland• 1962: Pierre Bezier put forward “Bezier curve” for the

representation of space curve• 1967: Wylie added lighting effect in objects representation• 1969: Xerox developed GUI (Graphic User Interface)• 1973: Richard Shoup invented Raster-Scan Display• The great improvement of graphic techniques

– Phong lighting model(1973)；Texture mapping(1974)；Ray tracing(1980)；Radiosity(1984)…





The History of Computer Graphics• Industry

– ILM(Industrial Light and Magic): an Academy Award winning motion picture visual effects company,1975

– SGI (Silicon Graphics, Inc): 1982– Pixar 1986– AutoDesk, Adobe

• Display card– 1994: the first PC display card --- by 3DLabs– 1995.11: Voodoo --- by 3DFx– 1999: Geforce256, the first GPU --- by nVidia– nVidia and ATI

• Geforce 8800、Radeon HD 2900 XT






• Graphics Standard– GKS(Germany, 1970’s); PHIGS(ISO,

1986); GKS-3D(1988)– OpenGL(SGI, 1992); DirectX(Microsoft);

Java3D(Sun)• Graphics Application Software

– 3DS Max, Maya, LightWave 3D– Renderman– AutoCAD, Solid Work





Computer Graphics Applications

• Computer Aided Design/Manufacturing• Entertainment• Education&Science and Training• Visualization in Scientific Computing• Graphical User Interface• ……





Computer Aided Design/Manufacturing (CAD/CAM)

• Computer aided design in airplane, car, watercraft, architecture, costume, toy…





CAD/CAM

• Boeing 777(1990.10 – 1994.4)– All the designing work is in computer

graphics stations and terminals– No paper

• Boeing 747(comparing)– 16320 meters paper!





CAD/CAM

Computer aided design/Manufacturing in airplane





CAD/CAM

Computer aided architecture design





CAD/CAM

Computer aided design in shoe Manufacturing





Entertainment

• Movies, Animations• Games• NPR (Non-Photorealistic Rendering)• ……





Special Effects in Movie

Jurassic Park（1993）





Special Effects in Movie

Titanic (1997)





3D Animation Movie

Monster’s Inc. (2001)Toy story (1995)





3D Animation Movie

Final Fantasy (2001)Skin Hair



Beijing Olympics opening ceremony





Games





NPR (Non-Photorealistic Rendering)

Calligraphy generated using computers

Toon Shading





Education & Science and Training

• Computer Aided Education and Science– Computer simulating the phenomenon in

biology, geography, physics, chemistry, medicine, political social, economy and other sciences

• Computer Aided Training– System for training of ship captains, aircraft

pilots …





NMT

Fractal modelsAerial views

Computer Graphics in Geography

• Terrain Generation

Landsat





Google Earth





Structure of Protein





Computer Aided Training



War games





Visualization in Scientific Computing

• Producing graphical representations for scientific, engineering and medical data sets and processes





Application --- Hydrodynamic

The air current around a car





Application --- Hydrodynamic





Application --- Weather

http://www.ssec.wisc.edu/~billh/vis5d.html

The isolines exhibit the distribution of atmospheric pressure





Application --- Medical

The visible human project





Graphical User Interface(GUI)

3D operating system



Graphic Devices in Computer System






• CPU– CPU implements all kinds of computations about

graphics such as description, construction and modification

• GPU(Graphic Processing Unit)• Video Display Devices• Input Devices





Video Display Devices

• Primary Output Device– Cathode ray tube(CRT) based display– Liquid-Crystal Display– Plasma panels

• Steroscopic Display• Three Dimensional Viewing Devices





Steroscopic Viewing Devices





Three Dimensional Viewing Devices





• Transport 3D display system• built by Hitachi Human Interaction

Laboratory (HHIL)

Three Dimensional Viewing Devices






• CPU• GPU(Graphic Processing Unit)• Video Display Devices: output devices• Input Devices





Input Devices• Primary Input Devices

– Keyboard, Mouse, Trackball, Spaceball, Joysticks, Digitizers, Light Pen, Scan machine, Touch panel, Voice System

– Data Gloves, Sensor, Tracker, Force Feedback



3D mouse Data glove

Force Feedback Device



Important conference:

SIGGRAPH(Special Interest Group on GRAPHics and Interactive Techniques)

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