CMPS 160 -- Fall 2009

CMPS 160 -- Programming Assignment 3

Due date:
9:00am FRI, 10/30/09

Objectives:

Learn and apply 3D transformations. More exercise with direct manipulation. Note that this program is much harder than the first two programs. Be sure to start early!

To Do:

Write a program that displays a 3D object in wireframe. Allow the user to manipulate the object using mouse and keyboard interaction. Do NOT use sliders.
Stage 1: (15% functionality)
- Create the XYZ axes of the world coordinate frame. Color the axes red, green, and blue respectively. Each axis should go from 0 to 50 units. Allow the display of these axes to be toggled on/off by pressing letter a. Default is to display the axes. The world origin should be at the center of your viewport. Your window must be at least 200x200.
- Read the enterprise model and display as a 3D wireframe. For simplicity, use orthographic projection with glOrtho. (Note: no extra credit given for shading/lighting since you'll be doing that in prog4). The enterprise data can be found in our repository of 3D models.
- As you read in the enterprise (or other 3D models), make sure that it is centered at the origin. The longest extent of the object should fit within a 100x100x100 box -- scale the object such that its longest dimension does not exceed 100.
Stage 2: (Translation : 15%) Allow the user to click and drag the enterprise around in screen space with the right mouse button. The enterprise should try to follow wherever the mouse is moved.
Stage 3: (Scaling : 10%) Allow the user to enlarge or shrink the enterprise with the middle mouse. If using rollers, rolling up and away from you should shrink the enterprise, and rolling down towards you should enlarge the enterprise. If dragging the mouse, drag up should shrink the enterprise, and drag down should enlarge the enterprise. You probably don't want to allow negative or zero scaling. Also watch out what happens when scaling an enterprise that has previously been translated.
Stage 4: (Rotation : 30%) Allow the user to rotate the enterprise in world space! While pressing the x key together with the right mouse, moving left or right should produce a negative or positive rotation about the x-axis respectively. Rotations about the y-axis and z-axis are achieved in a similar way by pressing either the y key with the right mouse, or the z key with the right mouse. Note that these are the axes going through the world origin, and not the axes that go through the object origin. Watch out when rotating an enterprise that has previously been translated -- it may suddenly disappear off the screen.
Stage 5: (Sequential transformations : 30%) Make sure that any sequence of translate, rotate and scale still works and produces the appropriate results. Note, sometimes the correct behavior is not the most intuitive behavior. See possible bonus items below for more intuitive behaviors.
Add a reset button (by pressing r) to bring the enterprise back to the origin of the world with the original size and orientation. This will become handy as you debug your program.
Possible bonus items:
- Have GUI that allows user to read in and manipulate more than one model -- about 5% bonus.
- Allow scaling and rotation transformations be relative to object coordinate frame instead of world coordinate frame -- about 5% bonus.
- Allow user to rotate object in screen space via a virtual trackball around the object's current position (as opposed to the world axes) -- about 10% bonus.

Grading:

This program nominally accounts for 6% of your final grade. We must be able to compile/test your code. Make sure that the code and accompanying make/project files, etc. are tested for successful compilation at least on the PCs in the lab. Also be sure to include the executable and a README file in your submission as to which platform to use. 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:

Submission must be done using the "submit" command from CATS.

submit cmps160-ap.f09 prog3 prog3.tar, or
submit cmps160-ap.f09 prog3 prog3.zip

This command should work from unix.ic.ucsc.edu. Create and submit a subdirectory called prog3. It should contain the executable and all the files you have to make your program compile/run. Tar or zip up prog3 before submitting.