Learn computer graphics from scratch and for free
scratchapixel.com
scratchapixel.com
Computer graphics needs more open education for sure. Traditional techniques are sealed in old books you have to go out of your way and find; Sergei Savchenko's "3D Graphics Programming Games and Beyond" is a good one. New techniques are often behind proprietary gates, with shallow papers and slides that only give a hint of how things may work. Graphics APIs, especially modern ones, make things more confusing than they need to be too. I think writing software rasterizers and ray tracers is a good starting point; forget GPUs exist.
Also, slight tangent, but there doesn't seem to be any contact method here other than Discord, which I find to be an immediate turn-off. Last time I checked, it required a phone number.
The donations page could use a link directly from the homepage too.
>Get Foley & Van Dam from the library
noting it should be available to check out, since I'd just checked it back in.
Several new editions since:
https://www.goodreads.com/book/show/5257044-computer-graphic...
https://www.goodreads.com/book/show/1933732.Fundamentals_of_...
I've been able to implement techniques based on such things without too much trouble. Also, Unreal is source available, although I haven't used its source to learn, and haven't checked the license for risks with doing so.
My username on here is after my (now older) game engine Reactor 3D.
I taught myself this stuff back when Quake 3 took over my high school. Doom got me into computers but Quake 3 got me into 3D. I didn’t quite understand the math in the books I bought but copied the code anyway.
Fast forward into my career and it’s been a pleasant blend of web and graphics. Now that WebGL/WebGPU is widely available. I taught PhD’s how to vertex pack and align and how to send structs to the GPU at my day job. I regret not continuing my studies and getting a PhD but I ended up writing Reactor 3D part time for XNA on Xbox 360 and then rewriting it half a decade later to be pure OpenGL. I still struggle with the advanced concepts but luckily there are others out there.
Fun fact, I worked with the guy who wrote XNA Silverlight, which would eventually be used as the basis for MonoGame, so I’m like MonoGame’s great grand uncle half removed or something. However,
Now that we have different ways of doing things, it demands a different kind of engine. So the Vulkan/Dx12/Metal way is the new jam.
Outside of playing with OpenGL as a teenager to make a planet orbit around a sun, a bad space invaders clone in Flash where you shoot a bird pooping on you, a really crappy Breakout clone with Racket, and the occasional experiments with Vulkan and Metal, I never really have fulfilled the dream of being the next John Carmack or Tim Sweeney.
Every time I try and learn Vulkan I end up getting confused and annoyed about how much code I need to write and give up. I suspect it's because I don't really understand the fundamentals well enough, and as a result jumping into Vulkan I end up metaphorically "drinking from a firehose". I certainly hope this doesn't happen, but if I manage to become unemployed again maybe that could be a good excuse to finally buckle down and try and learn this.
https://webgpufundamentals.org
or
https://webgl2fundamentals.org
I'd choose webgpu over webgl2 as it more closely resembles current mondern graphics APIs like Metal, DirectX12, Vulkan.
I was inspired by Zbrush and Maya, but I don't think I can learn what is necessary to build even a small clone of these gigantic pieces of software, unless I work with this on a day to day basis.
The performance of Zbrush is so insane... it is mesmerizing. I don't think I can go deep into this while treading university.
Vulkan isn't meant for beginners. It's a lot more verbose even if you know the fundamentals. Modern OpenGL would be good enough. If you have to use Vulkan, maybe use one of the libraries built on top of it (I use SDL3 for example). You still have freedom doing whatever you want with shaders and leave most of resource management to those libraries.
GPUs expose a completely different programming memory model, and the issue I would say is conflating computer graphics with GPU programming. The two are obviously related, don't get me wrong, but they can and do diverge quite significantly at times. This is more true recently with the push towards GPGPU, where GPUs now combine several different coprocessors beyond just the shader cores, and can be programmed with something like a dozen different APIs.
I would instead suggest:
1) Implement a CPU rasteriser, with just two stages: a primitive assembler, and a rasteriser.
2) Implement a CPU ray tracer.
https://haqr.eu/tinyrenderer/
https://raytracing.github.io/books/RayTracingInOneWeekend.html
Try adding various anti-aliasing algorithms to the rasteriser. Add shading; begin with flat, then extend to per-vertex to per-fragment. Try adding a tessellator where the level of detail is controlled by camera distance. Add in early discard instead of the usual z-buffering.
To the basic Whitted CPU ray tracer, add BRDFs; add microfacet theory, add subsurface scattering, caustics, photon mapping/light transport, and work towards a general global illumination implementation. Add denoising algorithms. And of course, implement and use acceleration data structures for faster intersection lookups; there are many.
Working on all of these will frankly give you a more detailed and intimate understanding of how GPUs work and why they have been developed a certain way, rather than programming with something like Vulkan, spending time filling in struct after struct.
After this, feel free to explore any one of the two more 'basic' graphics APIs: OpenGL 4.6, or D3D11. shadertoy.com and shaderacademy.com are great resources to understand fragment shaders. There are again several widespread shader languages, though most of industry uses HLSL. GLSL can be simpler, but HLSL is definitely more flexible.
At this point, explore more complicated scenarios: deferred rendering, pre- and post-processing for things like ambient occlusion, mirrors, temporal anti-aliasing, render-to-texture for lighting and shadows, etc. This is video-game focused; you could go another direction by exploring 2D UIs, text rendering, compositing, and more.
As for why I recommend starting with CPUs, only to end up back with GPUs again, and one may ask: 'hey, who uses CPUs any more for graphics?' Let me answer: WARP[1] and LLVMpipe[2] are both production-quality software rasterisers; frequently loaded during remote desktop sessions. In fact 'rasteriser' is an understatement: they expose full-fledged software implementations of D3D10/11 and OpenGL/Vulkan devices respectively. And naturally, most film renderers still run on the CPU, due to their improved floating-point precision; films can't really get away with the ephemeral smudging of video games. Also, CPU cores are quite cheap nowadays, so it's not unusual to see a render farm of a million+ cores chewing away at a complex Pixar or Dreamworks frame.
[1]: https://learn.microsoft.com/en-gb/windows/win32/direct3darti...
1) Implement 2D shapes and sprites with blits
With modern compute shaders, this has 95% of "How to use a GPU" while omitting 99% of the "Complicated 3D Graphics" that confuses everybody.
4 years ago I tackled exactly those courses (raytracer[0] first, then CPU rasterizer[1]) to learn the basics. And then, yes, I picked up a lib that's a thin wrapper around OpenGL (macroquad) and learned the basics of shaders.
So far this has been enough to build my prototype of a multiplayer Noita-like, with radiance-cascades-powered lighting. Still haven't learned Vulkan or WebGPU properly, though am now considering porting my game to the latter to get some modern niceties.
[0]: https://github.com/caspark/the-all-seeing-crab [1]: https://github.com/caspark/little-crab-tv
One Formula That Demystifies 3D Graphics
It's quite unfortunate that basically everyone thinks 3D graphics necessarily implies rasterisation and using someone else's API, and I feel extremely lucky to have taught myself in a time when you could trivially display images by direct memory access (mode 13h), and to have focused on ray tracing instead of rasterisation.
https://www.gabrielgambetta.com/computer-graphics-from-scrat...