Real-Time Computer Graphics

Also known as 15-472/672/772. Mondays and Wednesdays from 11:00-12:20 in Hamerschlag Hall B103 during Spring 2026. Taught by Jim McCann. Office hours after class in Smith 229 or by appointment.

Real-time computer graphics is about building systems that leverage modern CPUs and GPUs to produce detailed, interactive, immersive, and high-frame-rate imagery. Students will build a state-of-the-art renderer using C++ and the Vulkan API. Topics explored will include efficient data handling strategies; culling and scene traversal; multi-threaded rendering; post-processing, depth of field, screen-space reflections; volumetric rendering; sample distribution, spatial and temporal sharing, and anti-aliasing; stereo view synthesis; physical simulation and collision detection; dynamic lights and shadows; global illumination, accelerated raytracing; dynamic resolution, "AI" upsampling; compute shaders; parallax occlusion mapping; tessellation, displacement; skinning, transform feedback; and debugging, profiling, and accelerating graphics algorithms.

Previous iterations: Fall'24, Spring'24

Principles

This course is based on four principles:

• Do Things for Reasons -- if you don't understand why you are doing something, look deeper. (Corr: if you don't understand why someone else is doing something, ask.)
• No Magic -- (as much as possible) avoid black boxes and needless helper libraries.
• Test and Improve -- make things efficient through real-world testing. (Corr: asymptotic complexity is not the only factor; constants matter in the real world.)
• Go Big -- push systems to their limits.

Work

Your grade in this course will be determined by four assignments that cumulatively build a high-performance real-time renderer (60%); a project that adds a state-of-the-art feature to that renderer (30%); and participation in in-class discussions and activities (10%).

Don't Copy and Don't Steal

You will write a lot of code in this class, and I require that you actually type this code. (It is easy to copy-paste faster than you can think.)

You may use code from the internet, but make sure the code is not covered by a license that prohibits copying (copyright violation -- illegal!), be sure to include a comment citing your source (plagiarism -- immoral!), and make sure it passes through your brain on its way to your fingers (e.g., "fix" the coding style, re-work awkward parts, look up and document parts you don't understand).

You may work together, but take extra care to not copy code. Rule of thumb: if you are writing code, you should not be doing it where you can see your classmates' code.

Examples:

• GOOD: re-writing a documentation example in your own coding style (including a comment + URL citing your source).
• BAD: copy-pasting a stackoverflow answer or code snippet from the documentation, then re-working it in place. (You must type the code you use.)
• GOOD: working with a classmate to develop a design, then writing the code separately (and including a comment crediting the discussion in your code).
• GOOD: helping a classmate to debug their code, being inspired by their approach, and -- with your classmate's permission and a citation comment -- using a similar idea in your code.
• BAD: using copilot. (You aren't typing and you aren't thinking.)
• BAD: ChatGPT and similar. (Just bad in general. A copyright [or at least plagiarism] laundry.)
• GOOD: copy-pasting code you already wrote for this class.
• DISCOURAGED (but not forbidden): using autocomplete / codesense.

Resources

This course does not have a textbook; but you will likely find the following web resources helpful:

• C++ Reference.
• Compiler Explorer -- for playing with how code might get optimized.
• MDN's JavaScript reference.
• Node.js documentation.
• Blender Python API.
• Vulkan
  • Vulkan Specification -- latest; has better formatting than 1.3 .
  • Device Database -- check out feature availability on other GPUs.
  • Vulkan Guide -- easier reading than the spec!
• GLSL
  • GL_KHR_vulkan_glsl and GL_EXT_vulkan_glsl_relaxed -- describe language changes when using GLSL to create SPIR-V for Vulkan.
  • GLSL 4.5 Quick Reference Card (starts on Page 9).
  • GLSL 4.5 specification.
• Inspiration
  • Pouët -- a demoscene archive.
  • Shadertoy -- fun fragment shader hacks.
• Advances in Real-Time Rendering -- notes from SIGGRAPH courses.
• GPU Gems -- classic GPU programming books, available free.

See also: occasional "extra readings" links in sections below.

Schedule

Real-Time Graphics

Monday, January 12th

What it means to be real-time and general techniques for getting there.

• M Jan 12
• Course Overview; Core Principles
• Interactive, Real-Time, and Beyond
• Vulkan Intro
• Building the tutorial code (nakluV Step 0)
• renderdoc
• Javascript, maybe
• A0a For next class -- nakluV Step 1

Vulkan's view of GPUs

Monday, January 12th
-Monday, January 26th

How we get pixels onto the screen quickly. From attributes to framebuffers.

• M Jan 12 (cont)
• Command Buffers
• Render Passes
• Background Shader
• Push Constants
• Pipeline Creation
• W Jan 14
• Lines Shader
• Memory Types
• Memory Transfers
• Vertex Buffers
• Transform Matrices
• Descriptors
• Uniform Buffers
• Objects Shader
• Storage Buffers
• A0b For next class -- nakluV Step 2 and 3
• M Jan 19: MLK Day
• W Jan 21
• Swapchains and synchronization
• Headless mode
• Just initialization things
• A0c For next class -- nakluV Step 4, 5, and 6
• M Jan 26
• Vulkan Tutorial Wrap-Up
• Build systems
• RAII + Vulkan
• Benchmarking

Data Wrangling

Monday, January 26th
-Monday, February 2nd

Getting data into our renderer.

• M Jan 26 (cont)
• Scene graphs
• Instancing
• A1 statement walkthrough
• S72 intro
• A1 Scene Viewer out
• W Jan 28
• Data inflation: subdivision surfaces
• Sub-polygon detail: textures, normals, displacements
• Mesh compression?
• Texture compression
• M Feb 2
• least squares vertex baking(?)
• Creating (and finding) Bottlenecks
• Export scripts

Culling and Occlusion

Wednesday, February 4th

What you don't render can't slow you down.

• W Feb 4
• Bottlenecks
• Frustum culling
• Portal rendering
• Occlusion queries
• Geometry images

Materials

Monday, February 9th
-Monday, February 16th

Matching the real world, or doing better.

• M Feb 9
• detail with textures
• antialiasing
• physical materials
• A1 code share
• W Feb 11
• approximations and ground truth
• precomputation
• A2 introduction
• A1 Scene Viewer due (end of day)
• A2 Materials out
• M Feb 16
• procedural materials
• material capture

Color

Wednesday, February 18th

Primaries, white points, and encodings oh my.

• W Feb 18
• color spaces
• demo: P3 vs sRGB primaries
• demo: HDR

Going Big

Monday, February 23rd
-Wednesday, March 4th

Moving beyond what can fit in GPU memory.

• M Feb 23
• Terrains
• LOD streaming
• Mega-textures
• W Feb 25
• Nanite
• A2 Materials due (end of day)
• M Mar 2: Spring Break
• W Mar 4: Spring Break

Direct Lighting

Monday, March 9th
-Wednesday, March 11th

The first bounce of lighting is always the brightest.

• M Mar 9
• sphere, spot, and sun lights
• lambertian contribution from a spherical area light
• the "representative point" approximation
• A3 introduction
• A3 Lights out
• W Mar 11
• light loops
• light sorting

Shadows

Wednesday, March 11th
-Monday, March 16th

Solving the visibility problem.

• W Mar 11 (cont)
• shadow maps
• cubic shadow maps
• precomputed, voxelized shadows
• M Mar 16
• percentage-closer filtering
• soft shadows with PCSS

Screen-Space Stuff

Wednesday, March 18th

A few useful post-processing effects that didn't quite fit elsewhere.

• W Mar 18
• SSAO
• screen-space reflections
• order-independent transparency

Volume Rendering

Monday, March 23rd
-Wednesday, March 25th

Clouds, medical data, and fire.

• M Mar 23
• Nubus3
• A3 Lights due (before class)
• F Final Project topic selection
• W Mar 25
• raymarching smoke and clouds
• screen-space surfacing for liquids
• F Final Project out

Real-time Raytracing

Monday, March 30th

Just brute-forcing the lighting.

• M Mar 30
• raytracing in Vulkan
• sample sharing

Post-processing

Wednesday, April 1st

Fixing the pixels later.

• W Apr 1
• "scatter as gather"
• motion blur (a bit)
• bokeh

Rendering for VR

Monday, April 6th

The upsides and downsides of virtual reality.

• M Apr 6
• OpenXR APIs
• lens correction
• reprojection

Simulation

Wednesday, April 8th
-Monday, April 13th

Making things move without keyframes.

• W Apr 8
• Eulerian vs Lagrangian
• shallow-wave equations
• grid-based smoke
• particle-based smoke
• M Apr 13
• particle-based fluid
• particle-based solids
• filament-based smoke

Skinning and Animation

Wednesday, April 15th

Making meshes flexible.

• W Apr 15
• dual-quaternion skinning
• Skinned Mesh Animation

Miscellaneous

Monday, April 20th
-Wednesday, April 22nd

Topics that didn't fit elsewhere (thematically or temporally) and were interesting enough to bring up.

• M Apr 20
• sparse voxel octrees and sparse voxel directed acyclic graphs
• hierarchical ordered grids
• W Apr 22
• development of the 3DFX GPU
• F Final Project due (end of day)