The purpose of this FAQ is to answer the most commonly asked questions about homework and the course in general. This will be kept current, so you should check here first when you have a question.

### Homework 3

• Homework 3 web page

• Do you have any test images?
Yes. See the homework page for updates. Note that they are subject to change.

### Homework 2

I used
grade_hw2.rib with some varied parameters for grading. The following two images come from that file: (sorry about the jpg artifacts, but you get the idea).
180 fov 130 fov pitch = 1.3

The most common mistake people made was to not generate circular hex lenses, but rather to make the top and bottom flat as in the following image:

I allowed you to shoot the rays backwards from the eye, since that's what I did for the sample images.

• Homework 2 web page

• What exactly is the fov?
Perhaps a picture will help illustrate.

The fov is centered at the normal. Basically, the fov gives us a way to figure out which rays that fall under the lens don't need to get shot into the environment. You will, unfortunately, still need to shoot them out orthographically (see below for explanation). Assume the fov is rotationally symmetric for the flyseye lens system (ie after applying fov cutoff, you will be left with a circle of rays that strike the lens).

• Do we need to worry about negative parameters?
No. For this assignment, we are attempting to model a physical lens system. As such, you do not have to worry about negative fov, fov being greater than 180 degrees, negative pitch, pitch being smaller than 2*radius, or negative radius.

• What should I do with rays not striking a lens element, or rays that fall outside the fov?
Ideally, you would not have to trace them at all. However, the current build for lrt dosen't let you prohibit the tracing of a ray without mucking with camera.cc. Instead, it will suffice to return an orthographic ray.

### General Questions

• Where can I pick up handouts from class?
There is a filing cabinet in Gates 377 (3B copy room) with all CS 348B handouts in it.

• Is there any way to make more of the readings available online?
Unfortunately, copyright issues prevent us from making all the handouts available online. We will post electronic copies of everything we legally can.