CMP 161 -- Winter 2006

CMP 161 -- Programming Assignment 1

Due date:
12:00pm (noon), SAT, 1/28/2006

Objectives:

Implement some basic visualization techniques including: (a) interpolation, (b) pseudocoloring, and (c) glyphs.

To Do:

Write a program that reads in a sparse set of 2D velocity readings:
```
number_of_readings
xloc  yloc  xvec  yvec
xloc  yloc  xvec  yvec
...
xloc  yloc  xvec  yvec
```
For example, if the data set contains 5 readings, the file will have 6 lines. The first line will contain 5, followed by 5 lines, each one with 4 numbers. The 4 numbers correspond to the x,y location of the velocity reading followed by the x,y components of the velocity.
Example data: 20060430.txt
Interpolation: The first thing you are required to do is to interpolate the field to get a dense velocity field. You can do this with Shepard's inverse square distance interpolation. Other interpolation methods can also be offered as options to the users (optional for this program). Have a default of regular grid of 100x100 (optionally allow the user to change the grid resolution).
Pseudocoloring: Calculate the velocity magnitude at each grid vertex. Also calculate the gradient of the velocity magnitude using central differences -- assume no flux conditions at the boundary. Pseudocolor the field using the magnitude of gradient field.
- Provide the standard rainbow colormap to pseudocolor the 2D field.
- Provide a GUI that allows the user to interactively edit the colormap. User must at least be able to modify RGB mapping. Pseudocolor image should be updated as the map is being changed.
- Optionally allow the user to name, save, and reuse colormaps. Optionally provide the user with additional predefined colormaps.
Glyphs:
- Place an arrow glyph according to the velocity at each grid vertex.
- Color the arrows according to velocity magnitude.
- Allow user to globally scale the size of the arrow glyphs via a slider.
- Allow the user to reduce the number of arrow glyphs via a slider -- e.g. every other row and column, or every third row and column, etc.
Overlay: Allow the user to display both the pseudocolored surface as well as the arrow glyphs. You may want to position your glyphs slightly above the surface.
Documentation: Your README should describe any assumptions and critical design choices you made. For example, mention how the user should specify a data file, and how the bounding box for the interpolation grid is decided. Cite your sources for any chunks of code your borrow. If you turn my example code back in to me, I'll know its my own.
Example Code: There is an example of a simple method for adding a fltk GUI to a vtk application here: vtk-fltk-test.tgz

Items To Submit:

Html page with description and images of your project's output. Make sure your links are all local and relative to your submit directory.
Also make sure you have well documented code, makefile, README file, user guide, etc.
Do NOT include the data files in your submission.

Grading:

This program nominally accounts for 6% of your final grade. Include a README in your submission as to which platform to use. By the way, if you're doing your development on PC's, you should be able to recompile your fltk/opengl code on the suns with little or no modifications to your source. Programs turned in at least a full day early will earn 1% bonus credit. Late programs will be charged 1% late points. In addition, late programs will not be accepted 24 hours past due date. Late programs and reports will not be accepted for the final project. The bonus credits may be accumulated up to a total of 50% toward program and final project credits. Programs are graded 80% for functionality and correctness and 20% for style, readability, documentation/writeup, and efficiency. Additional points may also be earned for extra features.

Submission:

Create and submit a subdirectory called "prog1". It should contain all the files you have to make your program compile/run. Include the other items to be submitted in this directory as well. Submission must be done using the submit utility from CATS (e.g. unix.ic.ucsc.edu).

To submit use: submit cmps161-ap.w06 prog1 files
To verify submission use: peek cmps161-ap.w06 prog1