CMPS 160 -- Spring 2013

CMPS 160 -- Programming Assignment 3 (transformations)

Due date:
12 midnight, Friday, 5/17/12

Objectives:

This assignment covers the following components: vertex and normal transformations, picking.

Description:

This assignment will apply your knowledge of transformation matrices on objects. In all requirements below, you do not need to worry about camera manipulation yet (that's prog4). You can assume your camera is fixed. However, you do need to be able to apply different transformations to different objects in the scene.

Requirements:

20% of functionality: (bounding box) Read in the woman model from the data repository (see lab5). Create a bounding box for the woman model and render the bounding box as a wireframe. One way to do this is to scale a unit cube according to the largest dimension along 3 axes of the woman model. Display both the woman model (flat or smooth shading) and the bounding box (wireframe). Add GUI to turn rendering of the bounding box on or off.
20% of functionality: (translate) Allow the woman model to be positioned somewhere on the terrain. For this, you'll need a couple of things:
- Make sure that the woman is sized (scaled) properly relative to the terrain. You may or may not want to have a giant woman for example. To do this, assume that the fractal terrain you had before is in world coordinates. The woman model that you just read in needs to be scaled to the units of the world coordinate system before it's placed at the desired location.
- Support placement of the woman model using mouse drags. In translate mode (entered by first pressing letter "t" on the keyboard), left mouse down means woman model is about to be moved, left mouse up means that woman model is now at the desired location. You are still in translate mode in case you want to move the woman model elsewhere. You will need to map mouse movements in pixel coordinates back to world coordinates.
20% of functionality: (scale) Allow the woman model to be scaled-in-place. Scaling is uniform in all 3-axes. First, user enters scaling modeby pressing letter "s" on the keyboard. left mouse down and moving up will increase scale, and moving down will decrease scale. Left mouse up means done with scaling the woman model. You are still in scale mode in case you want to change the scale again.
20% of functionality: (rotate) Allow the woman model to be rotated-in-place. Here, we are interested in 2 different axes of rotation.
- about the axis lined up along head-to-toe i.e. rotation about this axis will make the model turn to its left or right or make an about-face. Let's call this her "vertical" axis.
- about the axis lined up along her left-right arms e.g. rotation about this axis will make the model lie down face up or face down. Let's call this her "horizontal" axis.
Note that these are different from the world Z and X axes since these are specified with respect to the woman model.
To carry out these rotations, the user enters the rotation mode by pressing either "v" (for rotation about her vertical axis) or "h" (for rotation about her horizontal axis). Then with left mouse down and dragging left or right to cause negative or positive rotation about the appropriate axis. Rotation is complete when left mouse is up. Rotation state left unchanged until the user enters a different transformation state.
Note that all transformations are cumulative. That is, if the model is currently lying down face up and you apply a rotate about her vertical axis, she will now by lying on her side. If you then translate the model elsewhere, she will move to the new position but will still by lying on her side.
20% of functionality: (multiple models) Add ability for user to read in additional models, or multiples of the woman model (see lab6). Allow the user to pick (see lab7) one of the models in the world and apply different transformations to it e.g. translate, rotate, scale.
Note that all the requirements from prog1 still applies. We will be building on top of this program in prog4 assignment by adding camera controls.

Resource:

XXX need to find good reference for picking --- Here's a good reference for picking

Grading:

This program nominally accounts for 8% 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 statically linked 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 a 1% late point. In addition, late programs will not be accepted 24 hours past due date. 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.s13 prog3 prog3.tar, or
submit cmps160-ap.s13 prog3 prog3.zip

This command should work from unix.ic.ucsc.edu. Create and submit a subdirectory called prog1. It should contain a statically linked executable and all the files you have to make your program compile/run. Tar or zip up prog1 before submitting.