Spring 2003 CS 780

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Spring 2003 CS 780
Advanced Topics in Computer Graphics (Non
Photorealistic Rendering)
March 5, 2003
Sung Yong SHIN CS Div, KAIST
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Outline
? Motivation ? Historical Perspectives ? NPR ?
Topics ? Conclusion
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? Motivation
A picture is worth a thousand words !!! How
would you better explain without pictures? What
kinds of pictures? Artistic pictures
Cartoons Technical illustrations Blue-prints M
ovie films
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What is the driving force behind computer
graphics? Photo realism? Can computer
graphics replace artists, illustrators, or
craftsmen? Why and why not?
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? Historical Perspectives
Physical world simulation Local
illumination Global illumination Plenoptic
function Image-Based Rendering Efficiency ?
Realism Human Perception NPR
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? NPR
How to communicate effectively? What is
important? How to abstract and represent? Mimic
artists techniques !!!
Science
Art
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Realism Impressionism ? Cubism Neo-realism
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Styles (Artistic Media Simulation) Pen-and-ink
illustrations Watercolor pictures Oil
paintings Engravings Mosaics Medium
Applicators Substrates
Papers, Canvas,
Blush types, Pencils,
Ink, Oil-paint, Acrylic, Watercolor, Graphite,
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2D Image based approaches Still images Video
clips 3D Geometry based approaches
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Issues
How to draw information ? What is important? -
Optical flows - Silhouettes - Creases -
Segmentations - Eye tracking How to represent
effectively (using strokes)? - Abstraction
(levels of abstraction) - Rendering - Scale
adjustment (blush sizes and types) How to achieve
temporal coherence?
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Approaches - User assisted - Fully
automatic Blush strokes Locations,
Orientations, Characteristics,
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? Topics

• Simulating artistic medium in 2D Papers 1 4
• Simulating artistic medium in 3D Papers 5 10
• Interactive techniques Papers 11 13
• Example-based simulation Paper 14
• Non-photorealistic volume rendering Paper 15
• Dithering and mosaic (2D) Papers 16 18
• Technical illustrations and art-based rendering
  (3D) Paper 19 - 20

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? Conclusion
NPR significantly enhances good images !!!
not a magic hand !!! Still in infancy. Is it
difficult to imitate real artists decisions? Can
computer program be expressive and have artistic
inventiveness? Can creativity be automated? Well,