chapter 2 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 2 PowerPoint Presentation
Download Presentation
Chapter 2

Loading in 2 Seconds...

play fullscreen
1 / 18

Chapter 2 - PowerPoint PPT Presentation


  • 318 Views
  • Uploaded on

Chapter 2 Graphics Programming 24 Jan 20067 Sierpinski Gasket pre-Mandelbrot classic found by W. Sierpinski around World War I. generated by recursivly dividing a triangle into four congruent smaller triangles think of the interior triangles as "holes”

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Chapter 2


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 2
Chapter 2
  • Graphics Programming
  • 24 Jan 20067
sierpinski gasket
Sierpinski Gasket
  • pre-Mandelbrot classic
    • found by W. Sierpinski around World War I.
    • generated by recursivly dividing a triangle into four congruent smaller triangles
  • think of the interior triangles as "holes”
  • they occupy more and more of the total area, while the "solid" portion becomes as hopelessly fragile
pseudocode
Pseudocode

1. Pick a point at random inside the triangle

2. Select one of the three vertices at random

3. Find a point halfway between the initial point and the randomly selected vertex

4. Display this new point by putting some sort of marker, such as a small circle, at its location

5. Replace the initial point with this new point

6. Return to step 2

pen plotter
Pen Plotter
  • moveto(x,y)
  • lineto(x,y)
problems with pen plotter model
Problems with Pen-Plotter model
  • 3D difficult
    • must convert 3d world to 2d projection explicitly
  • OpenGL allows us to focus on building 3D world and let computer handle projections
display funtion
Display funtion

Check programs online - lectures/chapter1/lab, boat

coordinate system
Coordinate System

3D COORDINATE SYSTEMS

Y

Y

Z

X

X

LEFT HANDED

RIGHT HANDED

Z

coordinate system in opengl
Coordinate System in OpenGL
  • What units are x, y, and z?
    • your choice
    • device independent
    • world coordinate system
  • Before displaying on output device, world coordinates must be converted to device or raster or screen coordinates
point to remember
POINT TO REMEMBER
  • We are studying computer graphics
  • We are not studying OpenGL
    • won’t cover all functions in OpenGL
graphics system as a black box
Graphics System as a Black Box

Function Calls

Output

User

Program

Graphics

System

Input/Output

Devices

Data

Input

api functions
API Functions
  • Primitive Functions
  • Attribute Functions
  • Viewing Functions
  • Transformation Functions
  • Input Functions
  • Control Functions
opengl what is it
OpenGL - What is it?
  • A graphics rendering library
  • API to produce high-quality, color images from geometric and raster primitives
  • Window System and Operating System independent
  • OpenGL “doesn’t do windows”
opengl
OpenGL
  • Most widely adopted graphics standard
  • Introduced in 1992
  • High visual quality and performance
  • Industry standard
  • Stable
  • Reliable and portable
  • Evolving
  • Scalable.
  • Easy to use.
  • Well-documented.
related apis
Related APIs
  • GLU (OpenGL Utility Library)
    • guaranteed to be available
      • tesselators
      • quadrics
      • NURBs, etc.
      • some surprisingly common operations, such as projection transformations (such as gluPerspective)
related apis16
Related APIs
  • GLX or WGL
    • bridge between window system and OpenGL
  • GLUT
    • portable bridge between window system and OpenGL
    • not “standard”, but uniformly popular
homework
Homework
  • Read Chapter 3
  • Assignment 2 - Program due 01/31/2007
    • Display your scene in 3D. Use at least 5 different graphics primitives.
glortho gldouble left gldouble right gldouble bottom gldouble top gldouble near gldouble far
glOrtho (GLdouble left, GLdouble right, GLdouble, bottom, GLdouble top, GLdouble near, GLdouble far)
  • Creates a viewing volume with a box shape.
  • Direction of projection is parallel to z axis.
  • Viewpoint faces -z axis.
  • glOrtho (0.0, (GLdouble) w, 0.0, (GLdouble) h, -500.0, 500.0);