CS 551851 Advanced Computer Graphics

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CS 551/851Advanced Computer Graphics

• David Brogan

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General Goals

• Learn more about graphics and animation
• Read and present SIGGRAPH papers
• Be aware of state of the art research
• Cover much of Parents animation text
• Understand fundamental techniques
• Learn by doing programming assignments

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Prerequisites

• Introduction to computer graphics
• Knowledge of textbook fundamentals
• OpenGL programming
• Use the computer as a tool to quickly build
  graphical applications
• Curiosity
• Class participation is required and the
  assignments will be dynamic

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This course does not

• teach how to use canned software
• We wont learn Maya or Photoshop
• require artistic skills
• focus on film making or animated cartoons
• Though we occasionally turn to these fields for
  insight and motivation

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Lets think about what weve learned already

• Virtual cameras
• Transformations
• Perspective
• Photorealism
• Decent lighting models
• Polygonal rendering
• Geometry algorithms
• Line/Plane equations
• Intersection computations

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Youre pretty smart already

• Among the studies of natural causes and laws, it
  is light that most delights its students. Among
  all the great branches of mathematics, the
  certainty of its demonstrations pre-eminently
  elevates the minds of its investigators.
  Perspective, therefore, should be preferred above
  all mans discourses and disciplines. In this
  subject the visual rays are elucidated by means
  and demonstrations which derive their glory nor
  only from mathematics but also from physics the
  one is adorned equally with the flowers of the
  other.

Leonardo da Vinci (1400s) quoting John Pecham
(1200s)
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But we labor on

• There are some who look at the things produced by
  nature through glass, or other surfaces or
  transparent veils. They trace outlines on the
  surface of the transparent medium But such an
  invention is to be condemned in those who do not
  know how to portray things without it, no how to
  reason about nature with their minds They are
  always poor and mean in every invention and in
  the composition of narratives, which is the final
  aim of this science

Leonardo da Vinci
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Advanced topics

• More realistic modeling and lighting
• Non photorealistic rendering
• Animation
• Optimization
• Perception

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What do these things mean to you?

• What do you think this course should be about?

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What do these things mean to you?

• Ideas from
• Video games
• Movie special effects
• Computer animated films
• Office of the future
• Video screens everywhere
• Ubiquitous computing

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Topics from textbook

• Curves
• Morphing/Warping
• Kinematics/Inverse kinematics
• Physical simulation
• Particle systems
• Implicit surfaces

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Topics from textbook

• Natural phenomena (plants, water, gas)
• Modeling and animating articulated characters
• Facial animation
• Motion capture

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Topics from SIGGRAPH

• Evolving Virtual Creatures
• Clouds
• Spacetime Constraints
• Artificial Fishes
• Tour Into the Picture
• Virtual Cinematographer
• Virtual Reality
• Others

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Other Topics

• Movie special effects
• The Making Of movies
• Traditional film making
• Traditional animation

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Potential Projects

• Build a curve editor / surface modeler
• Motion capture blending

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Potential Projects

• Plant modeling

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Potential Projects

• Particle system
• Physical simulation control systems

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Potential Projects

• Inverse kinematics of reaching arm
• Implement SIGGRAPH paper
• Tour Into the Picture
• Cloud Modeling

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Textbooks

• Rick Parent Computer Animation
• Frank Thomas and Ollie Johnson - Disney
  Animation The Illusion of Life
• Alan Watt and Mark Watt - Advanced Animation and
  Rendering Techniques
• Edward Dmytryk - On Film Editing
• Martin Kemp Science of Art
• Donald Bourg Physics for Game Developers

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Grading
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Perception

• Modeling perception really matters for computer
  animation
• We cant rely on four-hundred years of perception
  research by artists
• The best we have is eighty years of Disney
• In 1550, after 100 years of refining the art of
  perspective drawing, artists were shocked to
  think that the geometric purity of their modeled
  world didnt map to recent discoveries of the
  human eye. They couldnt even imagine how
  cognition affected what one saw. 200 more
  years would pass.

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Perception

• Positive afterimage (persistence of vision)
• the visual stimulus that remains after
  illumination has changed or been removed
• Motion blur
• Persistence of vision causes an object to appear
  to be multiple places at once

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Motion Blur

• Virtual camera in computer graphics usually
  shoots with infinitely small shutter speed
• No motion blur results
• Without motion blur, 30 fps results in fast
  moving objects that look like they are strobing,
  or hopping
• Would CG instantaneous snapshots produce motion
  blur if played at 300 fps?

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Whats the rate?

• Playback rate
• The number of samples displayed per second
• Sample rate
• The number of different images per second

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Animation Timeline

• First Animation
• 1896, Georges Melies, moving tables
• 1900, J. Stuart Blackton, added smoke
• First celebrated cartoonist
• Winsor McCay
• Little Nemo (1911)
• Gertie the Dinosaur (1914)

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Animation Timeline

• 1910, Bray and Hurd
• Patented translucent cels (formerly celluloid was
  used, but acetate is used now) used in layers for
  compositing
• Patented gray-scale drawings (cool!)
• Patented using pegs for registration (alignment)
  of overlays
• Patented the use of large background drawings and
  panning camera

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Brays Studio Produced

• Max Fleischer Betty Boop
• Paul Terry Terrytoons
• George Stallings Tom and Jerry
• Walter Lantz Woody Woodpecker
• 1915, Fleischer patented rotoscoping
• Drawing images on cells by tracing over
  previously recorded live action (MoCap)
• 1920, color cartoons

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Disney

• Advanced animation more than anyone else
• First to have sound in 1928, Steamboat Willie
• First to use storyboards
• First to attempt realism
• Invented multiplane camera

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Multiplane Camera

• Camera is mounted above multiple planes
• Each plane holds an animation cel
• Each plane can translate freely on 3 axes
• What is this good for?

Zooming, moving foreground characters off camera,
parallax, prolonged shutter allows blurring some
layers (motion blur)
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Stop-motion Animation

• Willis OBrien King Kong
• Ray Harryhausen Mighty Joe Young
• Nick Park Wallace and Grommit
• Tim Burton Nightmare Before Christmas