Transcript Chapter 3 BDIS - United International College

Computer Systems
and
Graphics
McGraw-Hill/Irwin
©2008 The McGraw-Hill Companies, All Rights Reserved
What is the goal of computer
graphics?
• High level, why computer graphics?
• Lower level, what is the computer doing?
Generating Images
• Images are made up of pixels
RGB
RGB Color cube (what we use in
computer graphics)
Other color spaces include HSV, YUV,
YCrCb, and YIQ
The “goal” of computer graphics
• Solve the function
– Red @ a pixel is f(i,j)=…
– Green @ a pixel is f(i,j)=…
– Blue @ a pixel is f(i,j)=…
Early Applications of Computer
Graphics
• Data Visualization
– Charts and Graphs
Early Applications of Computer
Graphics
• Computer Aided Design
(CAD)
– Q: Why wireframe?
• Why these apps?
– A: Better conceptualization,
interaction, transfer of ideas
Computer Graphics
Applications
• Virtual Reality
– VR: User interacts and
views with a 3D world
using “more natural”
means
– Best VR?
• Data Visualization
– Scientific, Engineering,
Medical data
– Visualizing millions to
billions of data points
– See trends
– Different schemes
Computer Graphics
Applications
• Education and Training
– Models of physical,
financial, social systems
– Comprehension of
complex systems
• Computer Art
–
–
–
–
Fine and commercial art
Performance Art
Aesthetic Computing
SIGGRAPH
• Games/Movies
Computer Graphics Applications
• Image Processing
– ~Inverse of Graphics
– Start with a picture
– Process picture
information
• Graphical User
Interfaces (GUIs)
– WIMP interface
– HCI
Overview of Graphics Systems
• Images
• Hardware
– Input Systems
– Output Systems
• Software
– OpenGL
Two Dimensional Images
• Images (at least
the ones in this
class) are two
dimensional
shapes.
• The two axes we
will label as X
(horizontal), and
Y (vertical).
+Y
Y
Axis
(0,0)
X Axis
+X
Hardware Pipeline
Input
Computation
Output
We want to draw a rectangle, how do we describe it to a computer?
Model (n) - object
description that a
computer understands.
Partition the space
(7,9)
(14,9)
(7,3)
(14,3)
1. Define a set of
points (vertices) in 2D
space.
2. Given a set of
vertices, draw lines
between consecutive
vertices.
Vertex (pl. Vertices) - a point in 2 or 3 dimensional space.
Record every position
Bitmap - a rectangular array of bits mapped one-to-one with pixels.
How do we do this?
Input Devices
• Locator Devices
• Keyboard
• Scanner
– Images
– Laser
• Cameras (research)
Locator Devices
When queried, locator devices return a
position and/or orientation.
•Mouse (2D and 3D)
•Trackball
•Joystick (2D and 3D)
Locator Devices
When queried, locator
devices return a
position and/or
orientation.
• Tablet
• Virtual Reality
Trackers
– Data Gloves
– Digitizers
Keyboard
• Text input
– List boxes, GUI
– CAD/CAM
– Modeling
• Hard coded
– Vertex locations are inserted into code
Scanners
• Image Scanners Flatbed, etc.
– What type of data is
returned? Bitmap
• Laser Scanners Deltasphere
– Emits a laser and does
time of flight. Returns
3D point
• Camera based research
– Examine camera
Many others
•
•
•
•
Light Pens
Voice Systems
Touch Panels
Camera/Vision
Based
• Which is best?
Common Modeling
Approach
• Hybrid
• Animator jobs
Computation Stage
Input
Computation
Output
• Now that we have a model of what we
want to draw, what goes on inside the
computer to generate the output?
Computation
Transformations
Rasterization
Computation Stage
Computation
Output
Model
Rasterization
Transformations
Transformed
Model
Displays in Virtual Reality
• Head-Mounted Displays
(HMDs)
– The display and a position
tracker are attached to the
user’s head
• Head-Tracked Displays
(HTDs)
– Display is stationary, tracker
tracks the user’s head
relative to the display.
– Example: CAVE,
Workbench, Stereo monitor
3D Glasses
3D Display
3D Object
Graphics Software
• Special purpose software
– AutoCAD
– Medical Visualization
– Paint
– Photoshop
– How about 3D modeling ?
3D Computer Animation
 Scientist and engineers used 3-D
computer animation to produce graphic
representations of the data.
 Entertainment industry used computer
animation and computer animation become
popular.
 In 1993, Hollywood released Jurassic Park
which captured the public's imagination
What is 3-D Computer Animation?
• Computer animation consists of a series of
individual images.
• These images are stored one at a time in the
computer. They are viewed at the normal
playback speed of 30 frames per second. The
result is a moving picture, or animation.
• 3-D animation allows the viewer to move around
the scene and change perspective over time.
 An animator is required to ensure that the animation
looks natural and believable.
Benefits Provided by 3-D Computer Animation
 A computer animation can graphically
simplify complex concepts which are
difficult to visualize.
 3-D computer animation captures attention.
 It can communicate more information, at a
faster rate, than an oral description can.
 Best of all, information presented as
moving images is retained by the viewer
for a longer time and with greater accuracy
Benefits Provided by 3-D Computer
Animation
 A computer animation can re-create an
event which is too expensive or too
dangerous to reproduce, such as an
aircraft accident.
 It can re-create a scene which has been
altered or which no longer exists, such as
a building which has been demolished.
 When used as an illustrative tool, computer
animation can help the presenter maintain
focus. It creates interesting presentation.
3D Computer Animation Software
 Maya
 the industry standard high-end 3D computer program.
Most of the popular computer games are made with
Maya software.
• 3D Studio Max
• 3DS MAX
– The world's most popular animation modeling, and
rendering solution for film, television, games and
design visualization
• Softimage,
• Lightwave
• Animator Studio
3-D Computer Animation is growing!
• 3-D Computer Animation is the world’s
fastest growing creative technology.
• 3-D dominates in the animated feature, game,
special effect, interactive, and commercial
industry
• Computer 3-D animation is taking over the
film world
– Computer Animated are breaking box office
records
– Computers are used for many of the special
effects in live-action films, and digitized actors.
• The field of 3-D animated video, computer,
and interactive games has grown amazingly
Principles of animation
• Animation is not easy. Each second of
computer animated video has 30 separate
images. The number of images that need
to be generated to create even a very short
film
Principles of animation
•
•
•
•
•
Modeling: Building objects and creatures from
primitive shapes, polygonal modeling, and/or sculpting
with curves and points.
Motion: Animating the objects and creatures you
model using key frames, path and shape animation,
simulation, deformation.
Character Construction: Creating skeletons,
attaching skins to skeletons.
Color and Texture: Creating, importing, and applying
multiple textures to objects/creatures; defining color,
reflectivity, and transparency.
Rendering: Lights, camera, compiling movies, adding
sound.
Jobs: Motion Picture Production &
Distribution
• Employment is projected to grow rapidly.
• Employment is centered in several major
cities, particularly New York and Los
Angeles
• Many workers have formal training, but
experience, professionalism, talent, and
creativity are the most important factors for
getting many jobs in this industry
CAREERS in Computer Animation
•
•
•
•
•
•
3D Computer Modeler
Animator
Art Director
Graphic Artist
Interface Designer
Multi Media Design Engineer
Some Example of Companies &
Computer Animated Films
• Pixar
The computer animation at Pixar have been
around since 1984
–
–
–
–
Toy Story,
A Bug's Life
Monsters, Inc
Finding Nemo
• Disney Pictures
Disney teamed up with Pixar to create films
• Dreamworks Pixar's main competitor
– Shrek
Famous Computer Animated movies
•
•
•
•
•
•
•
•
•
HARRY POTTER
THE LORD OF THE RINGS
THE MATRIX
MEN IN BLACK
MINORITY REPORT
SCOOBY-DOO
SOLARIS
SPIDER-MAN
STAR WARS
Resource
• Turgut Tezir , 3D Computer Animation
• www.cise.ufl.edu/CAP4730: Computational Structures in
Computer Graphics