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Math 149, Winter 2002

The Mathematics of Computer Graphics

• Official Information
• Description
• Virtual Office Hours
• Handouts
• Lecture Notes
• Linear Tranformation demo in Java
• Splines, Lagrange, etc.

Daily notes

• 3/14: Since we didn't get to the second method for telling if a point is inside a polygon (winding number method), it won't be on the exam. You may omit it from homework if you wish.
• 3/13: On the Sample Final (Handout MM), Problem (c) is on a topic you aren't responsible for, but you could try it anyway. It's like a spline basis function except that points at heights 0, 0, 1, 0 are used as B-spline control points rather than as data points to be interpolated.
• 3/13: On p. 4 of Handout KK, middle, there are some obvious misprints involving letters x and y.
• 3/12: In the on-line notes for 10-M, the first example of ray-tracing has been improved from the lecture.
• 3/5: As announced in class, the due date for Assignment #8 (Handout EE) has been changed to Monday, 3/11. Also, on that assignment, Problem FF-3 (not to hand in) should have been FF-4.
• 3/1: As announced in class, the nominal due date for Lab 2 was moved to Monday, 3/4, but if you have difficulties or questions let me know and we can make some arrangement. Some people had bugs that were hard to find.
• 2/26: The problems with lab 2 have finally been resolved, we think. Thanks both to the programmers and to those of you in the class who have helped (especially YLL).
  First, if you have tried to run GhostView and it crashes on you, and if you are someone who has had an account in the PIC Lab for some time, see below under "Ghostview crashes".
  To see the output of your "seeworld.exe" program:
  Copy your "seeworld.exe" program to a location on your Z: drive if it's not there already. Also, from the folder H:\class\m149.1\lab2 copy the files ez2gs.cmd and continents.dat to the same folder.
  Now get a DOS command line using the Start/Programs menu and run seeworld.exe -100 30 < continents.dat > earth.ez (with whatever latitude, longitude and output file names you choose).
  Then run ez2gs.cmd earth.ez
  If this doesn't run for some reason, you may still find a new file ez2gstmp.ps in your folder. This file contains the picture you want. You could view that in a window and double-click on it to view it.
  Note: If GhostView crashs for you, you may have an outdated .ini file for it. In Windows Explorer, go to c:\winnt\profiles\[User Name]\, find the file gsview32.ini, and rename it something irrelevant, like x. (Here [User Name] may have 000 after it.) Then the next time you run GhostView, the file should be regenerated properly. (If there is some permission problem that keeps you from renaming the file, let me know.)
• 2/22: The target due date for Lab #2 will be Wed. 2/27, since people are reporting problems running ez2gs.cmd in the PIC Lab. I'll try to have this fixed by Monday morning.
• 2/22: On Handout T, p. T 3, under Step S-4, it should say to use ez2gs.cmd instead of ez2gs.exe. Also, some people are having trouble running a shortcut to ez2gs.cmd, so it would be best to make an actual copy instead. (Thanks to YJK.)
• 2/21: People are asking about Problem S-19(b). All you need to do is to say which vertices make an octahedron and which make a cube and to make sure that using both all vertices are accounted for. Then the convex hull of the union of the octahedron and cube has to be the whole dodecahedron, because (1) it's no bigger than the dodecahedron since the cube and octahedron are inside, and (2) it's no smaller than the dodecahedron because the dodecahedron is the convex hull of its vertices and all vertices were included.
• 2/21: Important correction for Handout T: On p. T-9, the closing brace for the "while" loop should be lower down, after the check for visibility. [Thanks to G.G. and J.O. for the correction.]
• 2/14: On the sample midterm, if you try Problem 3 using the general method for projective transformations, make sure that A,B,C,D match up correctly with X, Y, O, E. For example, if your first matrix takes X to A, Y to B, O to C, E to D, so that its inverse takes A to X, etc., then your second matrix should take X to B, Y to C, O to D, and E to A, in order to have the product take A to B, etc.
• 2/13: On the solutions to the sample midterm, "quadrangle" should be "quartet", and the answer 5(d) is to a different problem. (Can you see what the problem was?)
• 2/8: Arcade results are compiled here . For some games there was wide agreement, but for others, disagreement. In some cases this may have been because scenes varied.
• 1/22: The PostScript example chi.ps for Lab 1B was in the wrong format and could not be edited with NotePad; it has been fixed. Please let me know of any further problems.
• The first week of classes we'll have a nonstandard schedule: Monday will be the TA section and Thursday will be a visit to the UCLA Visualization Portal. More details are on handouts.
• I'll be away for math meetings the first day of classes, so for any enrollment questions please send email. I may be able to respond. There are only a couple of spaces left in the class.