Fall 2004, 22C:151 -- Computer Graphics

Classes: TTh 9:30-10:45 am, 110 MacLean Hall

Professor: Chris Wyman E-mail: cwyman@cs.uiowa.edu (Preferred contact method) Office: 101J MacLean Hall Phone: (319) 353-2549 (Please use e-mail when possible) Office Hours: T 10:45 am - 12:15 pm, Office Hours: Th 1:00 pm - 2:30 pm, Office Hours: or by appointment	Teaching Assistant: Scott Davis E-mail: scodavis@cs.uiowa.edu Office: B20J MacLean Hall Office Hours: MW 11:30 am - 12:30 pm, Office Hours: or by appointment

Useful Information & Frequently Asked Questions:

Compiling on the Linux lab machines	Creating a CS web page	Submitting your assignments
Creating/extracting .tar.gz files	Setup Visual Studio to compile GLUT/OpenGL programs

Announcements (as of 11/11/04)

• (12/8/04) -- Homework 10 scores have been posted. An approximate cumulative percentage thus far has also been posted, to let you see the grades I will use to make letter grade decisions. These cumulative percentages are weighted by the correct values outlined in the syllabus (15% midterm, 5% updating your webpage, 65% homeworks). Obviously, since the final and homework 11 are not included, the cumulative percentages max out at less than 100%.
  
  
• (12/6/04) -- The review sheet for the final has been posted.
  
  
• (12/1/04) -- Two typos in Homework 11, both have been fixed now:
  • The first example image on the HW sheet is for value 20, not value 50!
  • If you downloaded a copy of the Linux source/executables before today, there is a typo in the readme! The environmental variable you want to set is LD_LIBRARY_PATH, not LD_LIBRARAY_PATH. It was correct everywhere except in the "setenv" command needed to set it up, so if you copied the command line, it would not work!
  
  
• (11/11/04) -- As I mentioned in class today, my notes did indeed contain a mistake in regards to computing the refracted direction. The notes have been fixed.
  • cos( theta_t ) = sqrt( 1 - f²( 1 - cos² ) )
    • where f = n_i/n_t, NOT n_t/n_i
  • Similarly, T = f * ( V + cos(theta_i)*N ) - cos(theta_t)*N.
  
  
• (10/29/04) -- NOTE: I don't think I was clear enough on this in class. To get the current light position, you can use glGetLight( GL_LIGHT, GL_POSITION, myLightPos );, but this returns the position in eye space, not world space! When you compute your projective shadow matrix, you need use the world space eye coordinates and a world space equation for your plane!
  • After calling glLightfv(), the world space coordinate for the light would then be myLightPos + currentEyePos.
  
  
  
• Older Announcements

Assignments:

• Homework 11 (Due Thursday, Dec 9)
  • Note: Make sure to update your webpage with images from this assignment!
  • Download the "shader_template" program:
    • Windows executables only or source.
    • Linux executables only or source
  • Information about vertex shaders (original detailed spec available here)
  • Information about fragment shaders (original detailed spec available here)
  • Another example vertex shader
  • (more information and samples soon)
  
  
• Homework 10 (Due Tuesday, Nov 30)
  • Note: Make sure to update your webpage with images from this assignment!
  • Here are the indices of refraction for assorted materials.
  • Here are some example images for this assignment: reflective material, shadow example, correct refraction, incorrect refraction, triangle example, pathtracing example 1, pathtracing example 2, and pathtracing example 3.
  • The C++ code for my Camera class and my main() and traceRay() functions.
  • The C++ header for my base Object class.
  • The C++ code for my Sphere class: header, source
  • The C++ code for my Diffuse material class: header, source
  
  
• Homework 9 (Due Thursday, Nov. 11)
  • To accommodate students with exams this week, the late policy will be temporarily changed (for this assignment ONLY) to:
    • Before Wednesday at midnight: (on time) (Max score: 30 pts)
    • Before Thursday at midnight: -5% (Max score: 29 pts)
    • Before Friday at midnight: -10% (Max score: 27 pts)
    • Before Saturday at midnight: -20% (Max score: 24 pts)
    • Before Sunday at midnight: -40% (Max score: 18 pts)
    • After Sunday at midnight: -100% (Max score: 0 pts)
    
    
  • Make sure you turn in a 512 x 512 image for the following scene (and describe how to get your program to regenerate it in the README file)
    • Eye at: (0,5,5), Looking at: (0,0,0), with Up Vector: (0,1,0).
    • Field of view in the Y-axis should be 60 degrees.
    • Red (1,0,0) sphere centered at (0,1,0) with radius 1
    • Green (0,1,0) sphere centered at (3,1,-3) with radius 3
    • Yellow (1,1,0) sphere centered at (-2,-3,2) with radius 2
    • Blue (0,0,1) plane with normal (0,1,0) running through point (0,-2,0)
    • Yellow (1,1,0) plane with normal (0,0,1) running through point (0,0,-7)
    • Light at: (-5,5,2) with color (1, 0.6, 1)
    • Here's an example result at 400 x 400.
    
    
  • Note: Make sure to update your webpage with images from this assignment!
  • Code to read/write PPM files as either a [tar/gz] or as a [zip].
  • Here are some C++ classes you can use or look at:
    • A vector class [tar/gz] or [zip]
    • A point class [tar/gz] or [zip]
    • Color & image classes [tar/gz] or [zip]
    • Assorted other classes & snippets [tar/gz] or [zip]
  
  
• Older homework assignments and related files are available here.

For those of you interested in playing with some vertex and fragment shaders before we get to them later in the semester, I have a simple example you can look at here. You can also try to compile that program to get your non-lab machine set up for later assignments.

Handouts/Slides:

• December 7: Review Sheet for the Final Exam
• November 11: Notes about reflection & refraction in raytracing (updated)
• October 26: Some Notes about TexGen, About transformation for shadow mapping, Steps for shadow mapping
• October 19: Mipmapping in OpenGL, Notes on Projective Shadows
• October 14: Midterm Key
• October 12: OpenGL Texture Routines split up into categories, with important functions in bold and descriptions of parameters useful for basic texturing.
• October 5: Midterm review sheet
• September 21: (My) Notes for Lecture
• September 9 & 13: Some notes for lecture -- note these aren't complete!
• September 2: (My) Notes for Lecture
• August 26: Basic GLUT functions, Basic GL functions
• August 24: Syllabus, Homework 1

Student Web Pages:

• Allen, Jessica
• Bhatarakamol, Naruedon
• Cardona, Juan
• Close, Corey
• Cooney, Chad
• Dusek, Jason
• Greene, Ryan
• Guy, Brett
• Hantzeas, Menny
• Holmes, Brandon
• Johnson, Chad
• Kanakares, Andy
• Kavanagh, Scott
• LaVoie, Chris
• Lewis, Chris
• McPeak, Justin
• Mo, Qi
• Monner, Derek
• Nichols, Greg
• Pan, Yan
• Pandurovic, Vladimir
• Park, Justin
• Pitzen, Chris
• Rudolph, Rudy
• Sun, Daniel
• Thiede, Tristan
• Weldon, Chad
• Wong, Charlie
• Xu, Neil
• Zhao, Fei

Helpful Links:

• The OpenGL Homepage (Documentation, specifications, and downloads)
• The Mesa Homepage (Documentation and downloads)
• Nate Robins' Win32 GLUT Page (Binaries and source, which should compile for non-Windows platforms too)
• The GLUI Homepage (Widgets for GLUT based OpenGL programs)
• The GLEW Homepage (Easy platform-independant access to OpenGL extensions)
• Cg Homepage (Information & downloads for nVidia's Cg)
• Sample Code from the Redbook, 4th Edition

• XV -- a simple, useful image manipulation tool that reads PPM files.
• GIMP -- a more feature complete (bigger) image manipulation tool that reads PPMs.
• Cygwin -- run all your favorite UNIX programs on Windows (including X, gcc, emacs, etc.)

• PPM file format description
• GLUT 3 Specification (PDF)
• OpenGL 1.1 State Machine Diagram (PDF)
• Cg Documentation (further down the page)

• SIGGRAPH -- The ACM's special interest group on graphics.

• On Academic Dishonesty and Cheating (more info here)
• On Missing/Rescheduling Exams
• On Arrangments for Disabled Students
• On Complaints (and who to complain to)

Last Modified: Friday, September 3, 2004

Chris Wyman (cwyman@cs.uiowa.edu)