In Fall 2023, CS 418 Interactive Computer Graphics is being offered in a way designed specifically to cater to our online MCS program. As such, both in-person and online students will be expected to consume course material in an asynchronous digital form. Office hours will also be held online, are optional, and will be the only synchronous component of the course.

1 Course operation

The course consists of the following components:

Pre-recorded lecture material
Available on the course content site, these are mostly fairly dense videos; I regularly distilled 3 hours of class into 1 hour of video by removing the Q&A and other interactive content. Please make notes of questions as you watch them and post those questions on CampusWire. I may answer them there or record videos explaining the answers and post them as supplementary content.
Pre-written lecture notes

Available on the course content site, these have roughly the same content as the videos, but often differ in level of detail. Some video content (such as coding demonstrations) have no corresponding notes.

Please make notes of questions as you read them and post those questions on CampusWire. I may answer them there or write up longer explanations and post them as supplementary content.

Per-module retakable quizzes

Lecture material is split into modules, each with a quiz. These quizzes are intended primarily as a self-assessment of learning and may be retaken as often as desired.

I understand that some students find quizzes annoying, but experience has shown me they they do help students find and fix gaps in understanding.

These quizzes are administereed on Coursera. You can activate your Illinois Coursera account as described in and then visit to access quizzes.

Machine problems (MPs)

There are five primary MPs, plus a sixth one required for 4-credit students but not required for 3-credit students. There are also two low-weight warm-ups intended primarily to smooth the way for subsequent MPs.

Machine problems are submitted on a custom course submission site that provides some limited automated feedback (mostly of the form did it run on our server); they are graded primarily by hand.

I expect each MP to take the average student between 10 and 20 hours to complete.

The 4cr MP typically takes a bit longer than the others, so 4cr students may wish to begin it early by viewing the raytracing videos and notes earlier than the 3cr schedule recommends.

No Final
This class has no final exam/quiz/project/assessment.

2 Course content

Computer graphics studies how computers can create images. Interactive computer graphics creates images quickly enough that a new image can be created in response to every user action. In principle any image-creation algorithm could be interactive, given adequate hardware, but in practice it usually refers to a specific family of workflows involving the interaction of the CPU and GPU. That family of workflows will be our primary topic in this class.

This course teaches the following in enough detail to implement them yourself:

  • How 3D computer graphics works, including both rasterization and raytracing.
  • How to use WebGL2, a popular GPU API, to create interactive 3D graphics.
  • How to generate your own 3D geometry, render it, texture map it, move it, and move the camera around it, with all of the underlying math and algorithms.
  • How to basic graphical motion simulation and particle effects.

This course teaches various other topics at a lower level of detail, including:

  • Shadow maps
  • Deferred shading
  • Keyframe animation and tweening
  • Various fractals
  • Various texture mapping techniques
  • Physically-based rendering techniques
  • Inverse kinematics
  • Rigid-body, soft-body, and fluid dynamics

This course does not teach

  • OpenGL, Direct3D, Metal, Vulkan
    • WebGL2 is related to them and will help you understand them too.
  • Artistic content such as 3D modeling, animation, rigging, texture creation, light setups, etc.
  • Allegro, Banshee, C4, CryEngine, Godot, Intrinsic, OGRE, SDL, Serious, Source, Torque, Unity, Unreal, UX3D, Xenko, XNA, …
    • We discuss techniques used to build these tools, but not how to use them.
    • CS 415 uses one of theses.
    • The GameBuilders RSO often uses these tools.
  • Computer game design
  • Computer vision
  • 2D graphics
    • We’ll mention some topics in passing, but CS 445 is more relevant
  • Advanced raytracing, path tracing, importance sampling, and other movie-quality graphics content
    • CS 419 teaches this, but is offered infrequently.

3 Grading

My goal in this class is that you learn. As it is an elective, I hope most of you are taking it for the same reason. But I do have a duty to assign grades, so here’s how we’ll do it.

Weight Assessment
70% MPs
30% Quizzes

Numbers are converted to letters linearly with the A−/B+ cut-off at 90% and the C−/D+ cutoff at 70%; more precisely

const letter_grade = (percentage_earned) => {
    if (percentage_earned <= 60) return 'F'
    let letter = 'DCBA'[Math.floor(percentage_earned/10 - 6)]
    if (letter != 'A' && percentage_earned % 10 > 20/3) letter += '+'
    if (percentage_earned % 10 < 10/3) letter += '-'
    return letter

MP points come in two groups: core and elective. Core MP components are mostly things that every graphics students should know, with some additions that are prerequisite for many other tasks. Elective MP components go beyond the minimum, and you’ll get to pick and chose which ones you do. The number of MP points of each type you will need, together with a list of MPs, can be found on the MPs overview page

4 Cheating

I already know the answers to all the quiz questions and have already implemented all the MPs. It’s the learning you gain by doing MPs and by realizing what wasn’t as clear as you thought by doing quizzes that matter to me. As such, not doing your own work is the primary way of cheating.

Module quizzes are open-book and retakable, but do not use live or interactive help on the module quizzes and do not share answers with anyone.

The MPs require you to write all of your own code, with some exceptions called out explicitly in the MP descriptions. Write your own code also means design and understand it: simply writing what someone else tells you to write does not contribute to you learning and is cheating. Within this constraint you may use any source to assist you, but cite all such sources in comments in your code to avoid plagiarism. As an exception, you do not need to cite course content provided as part of this course this semester, nor do you need to cite interactions with this semester’s official CS 418 course staff.

5 Prerequisites

Listed prereqs in the course catalog are

CS 225 Data Structures

Needed for

  • Experience with C or C++. We won’t use those languages, but GLSL which we will use is based on them.
  • Comfort with the idea of pointers, binary encoding of data, and memory.
  • Three semester of programming experience.
A linear algebra class

Needed for

  • Familiarity with matrices and vectors. We’ll use vectors to represent 3D points and matrices to transform them, and also use vectors to represent lists of properties of a point.

We will discuss using large sparse matrices to represent systems of equations and variants of conjugate gradient to solve them. That is rarely usable at interactive speeds, so we won’t talk about then in much detail in this class.

MATH 241 Calculus III

Needed for

  • Comfort with Euclidean space and the 3D vectors
  • experience thinking in 3D that multivariable calculus provides

There is some calculus in graphics, but mostly as theoretic background for algorithms that do not themselves use the calculus. We’ll not need any integral-solving or related by-hand calculus computations in this course.

6 Course Staff

Name Luther Tychonievich
Office 2340 Siebel
Phone +1 217 333 8609
Email luthert@...
Include 418 or graphics in the subject line
Soorya Shimgekar, Chen-Chi Fan, Sean Koo, Carlos Conley, Satvik Pandey
By invitation only. I get daily roster change update digests and enter them into CampusWire when I do.
Office Hours
Location Zoom meeting 854 0421 4284 passcode 418

7 Textbook

Readings are hosted for free on There is no other textbook required.