2022 November 13,

CS 311: Computer Graphics

Carleton College, Fall 2022, Joshua R. Davis, , CMC 324, x4095

Introduction

This course is an introduction to computer graphics. We focus on the two main algorithms for three-dimensional graphics: triangle rasterization and ray tracing. These algorithms produce almost all of the 3D imagery seen in computer-generated films, video games, scientific visualizations, etc. The course proceeds in three stages:

1. We begin with a minimal programming interface that lets us make a window and set the colors of its pixels. Atop this primitive foundation we implement 2D triangle rasterization, interpolation, fragment and vertex shaders, and meshes. Then we transition to 3D and add depth buffering, projections, clipping, etc. In other words, we implement our own 3D graphics engine like (the core of) OpenGL, Vulkan, Direct3D, or Metal.
2. We re-write our triangle-rasterizing graphics engine to use the graphics processing unit (GPU). To understand some key concepts, we first learn a little OpenGL history. Then we use Vulkan to do the work. We add features such as scene graphs and Phong lighting.
3. Returning to the same minimal programming interface as in the first part of the course, we implement as much ray tracing as time allows. Features include shadows, mirror reflections, and either transmission or hierarchical bounding volumes.

Graphics is a big field, so there is much that we don't cover: other 3D algorithms, most 2D algorithms, image processing, etc. Also, we spend as little time as possible on artwork. We are not making a polished film or game. Rather, we are making a technological foundation, upon which someone could build a film or game.

The prerequisite for this course is CS 201: Data Structures. We might use some of its specific content, such as graphs and stacks. More importantly, students must have maturity in thinking algorithmically and learning on their own. I provide tutorials about the C programming language and basic linear algebra, but I don't spend much class time on them. Talk to me if you are concerned about your background. I am happy to help you learn the necessary skills. :)

Responsibilities

You should expect to work hard and learn a lot. The College's accreditation says that a 6-credit course is 150 hours of work. That's about 15 hours per week or 5 hours per class meeting. Those 5 hours break down into about 1 hour for class itself and 4 hours for homework, reading, studying, etc. If you find yourself spending less time and struggling, then talk to me. If you find yourself spending much more time, then talk to me.

For better or worse, we are required to measure your learning using grades. The following elements contribute to your numerical grade.

• Participation (5%): Our class meets in CMC 301 during period 5A (MonWed 1:50-3:00, Fri 2:20-3:20). You are expected to attend every class meeting, take notes, participate in discussion and group work, and ask and answer questions. You can make up for a deficiency in class participation by talking with me in office hours. Additionally, you are required to visit me in office hours some time during the first two weeks, even if just to say "hi". It helps us break the ice. :)
• First project (30%): The software triangle rasterization project takes about four weeks. In each class meeting, we learn a new concept or algorithm, which you implement in code before the next meeting. At the end of the project, I grade it by testing certain milestones and inspecting the code. Also, our grader grades your code a bit along the way. Late work is eligible for full credit, if it's submitted by the time it's graded. However, it is crucial that you keep up with the work as much as possible, because each day's code builds on the previous day's code. Therefore, as soon as you miss a deadline, e-mail me to tell me so. Then we can formulate a plan to get you back on track.
• Second project (20%): The hardware triangle rasterization project is similar but only about two weeks long. It uses some of the code from the first project.
• Third project (25%): The ray tracing project is similar but takes about three weeks.
• Exam A (10%): This exam is given sometime during the first project. It tests your understanding of the material thus far. For example, I might ask you to explain your code. The exam might be oral in-person or written take-home. I haven't decided yet.
• Exam B (10%): This exam is similar but given later in the term — maybe during the third project?

Numerical grades are converted to letter grades only at the end of the term. There are no predetermined percentages (90%, 80%, 70%, etc.) required for specific grades (A, B, C, etc.), because I cannot write assignments and exams that are so precisely tuned. Instead, I assign letter grades by comparing students' scores to the course goals. For example:

• A student, whose polished code passes nearly all tests, and who demonstrates thorough understanding on the exams, earns an A.
• A student, whose less-polished code passes most tests but fails a few, and who demonstrates not-quite-complete understanding on the exams, earns a B.
• A student, who demonstrates effort and learns much of the material, but who has significant gaps in their understanding and implementation of major concepts, might earn a C.
• A student, who skips an entire project or exam, does not pass the course, even if they do well on the other projects and exams. To pass the course, you must pass each part of the course.

In general, you may not copy someone else's work or allow them to copy yours — in person, over the Internet, etc. Presenting someone else's work as your own is an act of academic dishonesty. The College requires me to report you if I suspect that you have not upheld its Academic Integrity standards.

In class, photographs and recordings are not permitted without my prior approval. Phones are not permitted, except for the purpose of approved photographs and recordings.

Resources: Help Yourself

If the preceding section is bad news, then these next few sections are good news. You are supported with multiple ways to learn the material. :)

Here are the three projects that make up the bulk of the course. The instructions are pretty detailed.

• Triangle Rasterization in Software (including the first day's homework)
• Triangle Rasterization in Hardware
• Ray Tracing

Here are exams from this term and two earlier terms, with solutions and quartiles (75th, 50th, and 25th percentiles). Keep in mind that the topics vary slightly from term to term.

• Fall 2022 Exam A, Solutions (19/20, 18/20, 17/20)
• Fall 2022 Exam B, Solutions (16/18, 14/18, 13/18)
• Winter 2021 Exam A Problems, Solutions (14/15, 13/15, 12/15)
• Winter 2021 Exam B Preparation, Problems, Solutions (22/24, 20/24, 18/24)
• Winter 2021 Exam C Preparation, Problems, Solutions (17/23, 16/23, 14/23)
• Winter 2019 Exam A Problems, Solutions (52/60, 48/60, 42/60).
• Winter 2019 Exam B Prompts and Common Answers (37/41, 34/41, 30/41)
• Winter 2019 Exam C Problems, Solutions (51/60, 49/60, 45/60).

Here are some other resources produced by me specifically for this course.

• Unix Tutorial tells you what you need to know and not much more.
• Installation Instructions help you set up the required software on your own computer, if you don't want to use the CS lab machines in Olin.
• Debugging Ideas might help you avoid frustration.
• Further Reading gives you some ideas for what to study next in graphics.

Here are some external resources. There is no official textbook.

• Fundamentals of Computer Graphics by Marschner and Shirley. One copy of this book is on two-hour reserve in the library. This would probably be our textbook, if we had one. It can give you a treatment of the concepts that is different from mine.
• The Descent to C is a conceptual explanation of C intended for programmers coming from higher-level languages such as Java and Python.
• Official Vulkan Web Site has a lot of material.
• Mounting Network Drives helps you electronically submit your project work.

Resources: Your Partner

For the first week of the course, you are required to submit individual project work. You are encouraged to work in the same room with other students and bounce ideas off them, but the work that you submit for grading must be your own.

After the first week of the course, I assign partners. (You have the opportunity to express some preferences. You may also opt out entirely and work alone.) You keep your partner for the remainder of the first project, unless the partnership turns out to be dysfunctional. You and your partner develop a single code base, with both of your names on it, and submit a single copy for grading. Again you are encouraged to bounce ideas off other groups, but the work that you submit must be done by your group.

When we start the second project, I assign new partners based on another poll of your preferences. You keep your partner for the whole project.

When we start the third project, I again assign new partners for the whole project.

Resources: Other

I hold office hours several times per week. See below for the schedule. No appointment is needed; just drop in! If you cannot attend office hours, then consult my weekly schedule and e-mail me, listing several times at which we could meet.

Our course staff member, PJ (), helps you in two ways. First, he provides preliminary grading of your projects before I grade them. Second, he too holds some office hours in the lab.

For help with linear algebra and other math, you can also visit the Math Skills Center on the second floor of CMC. It is reasonable to consult books or the Internet for help with math, C, or Vulkan details. For help with graphics material, I prefer that you don't consult the general Internet; please use me, PJ, your classmates, or the resources listed on this web site instead.

Our course should be welcoming to all students, regardless of their identities, backgrounds, and experiences. We should all be resources to each other rather than hindrances. Please let me know if anyone — a classmate, a lab assistant, or I — do anything to make you feel otherwise.

If a health condition or other personal matter affects your participation in class, homework, exams, etc., then please let me know as soon as possible. Depending on the situation, we might want to confer with Accessibility Resources, Assistive Technology, Student Health and Counseling, or Sexual Misconduct Prevention and Response. When you ask me to help, I do my best to help. :)