Fall Quarter 2001

Purpose

The purpose of this lab is to develop an understanding of how three-dimensional computer graphics applications are implemented.

Acknowledgement

This lab was developed by Dr. Henry Welch.

General Lab Information

Implement a simple 3-D graphics system for drawing the wireframes of polyhedral objects.

As a minimum your package should do the following:

1. Allow the specification of polyhedra using files. The files lab8a.dat (a cube), lab8b.dat (a tetrahedron), and lab8c.dat (a duck) contain examples which specify a polyhedra as a set of edges. (i.e., There are two 3-D points per line. This is not the best long term specification, but it is sufficient for the requirements of this assignment.) You may find it necessary to edit these files to conform to your image::Read; feel free to do so.
2. Place the origin of the world coordinate system in the center of the drawing area/viewport.
3. Position the observer at infinity and specify the direction of view using a compass angle (with vertical up on the screen which defines north and corresponds to 0 degrees) and an angular displacement from vertical with 0 degrees being straight down. Think of this as the point of view taken by someone looking down from an airplane (like looking at a map with vertical relief). The compass heading controls which way is up and the climb or descent of the aircraft allows us to see the "front" or "back" of the object as well as the top. This in effectively a spherical coordinate system (i.e., angle from z and angle around z in the xy plane). This leaves the view-up direction somewhat ambiguous. Assume it starts aligned with due north and rotates with the spherical angles.
4. Allow this orientation to be changed using the command line or other mechanism while your program runs. You may want to experiment with the dial, slider or spinbox controls. To use these properly you will need to learn about signals and slots within Qt. You can also easily insert the controls using the QVBoxLayout widget called mainLayout in the shell.
5. It is NOT necessary to develop a polyhedra class you may do this all with lines. (This will, however, make it difficult to do surface effects which we may ultimately want to implement.)

Note: This lab is worth double credit (200 points)

Application demonstration

You should demonstrate the successful operation of your application before or during last formal meeting time (lab or lecture) during week 10. (Section 1: Friday class, Section 3: Thursday class, Section 4: Friday lab)

Note: for full credit, you will need to be able to demonstrate your application using the terminology described in this assignment. (It is not sufficient to just say, "See, I can make the duck spin on it's tail.")

Lab report (due 11pm, the day prior to your demonstration due date)

The lab report need not be self-contained. Your report should include:

• Discussion including:
  • A tally of the number of new Non-commented Lines Of Code (NLOC) written for this lab assignment. You should use the CLC perl script on your code. If possible, break the NLOC down into the various features you needed to implement.
  • A summary of your activity log indicating how much time you spent on each phase of the assignment. Please report the time in the following categories:
    • Designing
    • Coding
    • Debugging (before you think it's working)
    • Testing (after you think it's working)
    • Report writing
    • Other
  • A brief narrative -- the problems you encountered, how you solved them, and what you learned.
• Documented source code (clearly identifying any changes made since your last submission) Note: you should include all the source code necessary to compile your project except for unmodified source code written by Dr. Welch. For example, you don't need to include shell.cpp if you didn't modify it.
  You may wish to use gensrc, a shell script which will produce an XML document that may be used as a starting point for your report. The file will include all of the source code files (provided you modify the script appropriately... edit gensrc for details on how to do this.)
• Extra credit is available but only if it is clearly identified during the demonstration and in your report.
• Be sure to address any areas concern from previous submissions.

As with any report you submit, correct spelling and grammar are required. In addition, your report should be submitted electronically following the Electronic Submission Guidelines. (You may wish to consult the sample report before submitting your report.) Be sure to keep copies of all your files, in case something gets lost. It may be wise to keep a diskette backup as well.

If you have any questions, consult the instructor.