Computer Graphics CSC 830

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Computer GraphicsCSC 830

• Lecture 1
• Introduction

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Administrative information

• Who am I? Dr. Ilmi Yoon (TH910), yoon_at_cs.sfsu.edu
• Course web site (csc830_at_thecity.sfsu.edu)
• TA Jun Murakawa
• 5 assignments (indivisual) 1 term project (team
  project) Advance topic presentation
• Going over syllabus

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Goals for this semester

• Learn the fundamental techniques involved in
  computer graphics
• Learn the standard computer graphics API and
  rendering withOpenGL
• Implement 3D rendering pipeline Modeling and
  Animation

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What is computer graphics?

• Computer Graphics is making pictures from models
  (representation) using the computer
  (computational algorithms)

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Why Computer Graphics?

• Movies
• Games
• Simulation
• CAD-CAM
• Architecture
• Virtual Reality
• Visualization
• Medical Imaging

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Movies
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Games
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Simulation
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CAD-CAM Design
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Architecture
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Virtual Reality
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Visualization
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Medical Imaging
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The Graphics Rendering Pipeline

• Rendering is the conversion of a scene into an
  image.
• The scene composed of models in 3D space.Models,
  composed of primitives (points, lines, polygons,
  etc), supported by the rendering system. Models
  entered by hand or created by a program. (In our
  class, models already generated.)
• The image drawn on monitor, printed on laser
  printer, or written to a raster in memory or a
  file. These different possibilities require us to
  consider device independence.
• Classically, model'' to scene'' to image''
  conversion broken into finer steps, called the
  graphics pipeline. Commonly implemented in
  graphics hardware to get interactive speeds.

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The Graphics Rendering Pipeline
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The Graphics Rendering Pipeline

• A number of coordinate systems are used
• MCS Modeling Coordinate System.
• WCS World Coordinate System.
• VCS Viewer Coordinate System.
• NDCS Normalized Device Coordinate System.
• DCS or SCS Device Coordinate System or
  equivalently the Screen Coordinate System.

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Topics in CG - Fundamentals

• Computer Graphics involves a lot of mathematics
  (Linear Algebra)
• Points, normals and operations on them, dot
  product, cross product

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Topics - Transformation

• Transformations Translation, Rotation, Scale
  (the basic rigid transformations)
• Rotations around an arbitrary axis can be
  represented by a set of rotations around the
  world axis

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Topics - Transformations

• Other types of transformations Shearing,
  Tapering, Twisting, Bending (Deformation)

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Topics - Coordinate Systems

• Transformation between Coordinate systems
• Object, World, Camera, Normalized Device, Window
• Perspective and Orthographic projection

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Topics - Rasterizing Lines

• Line drawing algorithms

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Topics - Rasterizing Polygons

• Half-space Test
• Scan-line Algorithm
• Crows algorithm
• Flood Fill

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Topics - OpenGL

• Graphics API standard
• Has an Architectural Review board
• OpenGL is a state machine
• OpenGL is a primitive-based renderer (vertices)
• OpenGL is independent of the windowing system

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Topics - Visibility

• Clipping
• Cohen Sutherland, Liang Barsky

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Topics - Visibility

• Culling
• Backface Culling

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Topics - Visibility

• Hidden surface removal
• Object Space Algorithms
• Warnock
• BSP
• Portals
• Image Space Algorithms
• Ray casting
• Painters
• Z-buffering

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Topics - Shading
Determining the light traveling from a point in
the scene to the viewers eye
Images courtesy of Watt, Watt Watt, and Foley
van Dam
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Topics -Sampling/Antialiasing

• Problems with undersampling aliasing

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Topics - Texture Mapping
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Topics - Texture Mapping

• Projection texture
• Mip-mapping (image pyramids)
• Environment map(reflective surface), refraction
  map, opacity map, illumination map, bump map,
  displacement map
• 3D Textures (via noise and turbulence)

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Topics - Shadows
Accentuate 3D effects
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Topics - Surfaces

• Representing smooth surface geometry using a
  finite set of control points and a set of basis
  functions
• Bezier Curves, B-Splines, Uniform B-splines,
  Non-uniform B-splines, Non-uniform Rational
  B-splines (NURBS), Subdivision curves and
  surfaces, Implicit Surfaces.

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Topics - Surfaces
424,376 faces
60,000 faces
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Topics - Surfaces
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Topics - Animation
Zelda (GameCube) Realtime animation
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Topics - Animation

• Final Fantasy

Pixar movies
Offline Animation
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Topics - Advanced Rendering

• IBR (Image-based rendering)
• Light Field Rendering
• NPR (Non-Photorealistic Rendering)

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Topics

• And many more.
• What do you want to learn?