Is there a collection of these somewhere?
https://imadr.me/pbr/ (physically based rendering)
oh wait, (2020) :(
thankfully i don't remember much from this one, so was able to extract some dopamine from it still
I can't wait until one of my kids, who seems very interested in physics-adjacent topics, is old enough to go through these pages with me.
* https://en.wikipedia.org/wiki/Inverse-square_law
I know a good number of photographers can struggle with it when they're getting into flash/strobe photography (even though may be good with f-stops generally, the moving of the flash stand appropriately takes some mental 'accounting').
edit: And now after rtfm I see there's a nice demo of this!
A recent example,
https://www.france24.com/en/tv-shows/focus/20260106-back-to-...
Notice how few equations there are in this page, it is a common feature of edutainment, they won't give you equations unless they can't get away without. No linear algebra here, just a cosine (actually a dot product in disguise) and the inverse square law (1/r²), two equations he considered too fundamental to skip. Also notable is the lack of exercises.
But now that you have read this page, and played with the interactive elements, you probably have a good understanding of how lights and shadows work, but can you write a 3D engine or even just calculate exposure time without your camera helping you? Without prior knowledge, probably not. For that, you actually need to do the maths, with exercises and all that. And by the way, look at the source code (it is not obfuscated), all the linear algebra that is not present in the article is there!
That, I think, explain the discrepancy between edutainment and textbooks. Textbooks are for you to do actual work, do the maths, solve problems, etc... not just give you an overview. That's also why is takes way longer and requires a lot more effort on the student part.
Interactive content like this one is good, and maybe it should be given a bit more consideration by the traditional educational system. But I don't think it can replace textbooks, at least not for the "hard part".
Maybe this is just personal preference. I knew capable students who were wrote and prescriptive in their approach to the courses, but I was closer to those who played in the conceptual end of the pool.
I once made a resource like this site for my own educational benefit when I was grappling with MR physics. You're right - I had to do the math(s)! - and came away with a much clearer understanding of the subject. Still, I received lots of correspondence from students and professors who found the visual aid helpful on their journey.
He has a Patreon page, if you want to support https://www.patreon.com/ciechanowski
All combined, he may get a few thousand dollars per article, which I admit is not much for what we get, and certainly not enough to make a living.
Bret Victor [0], Andy Matuschak [1], and Seymour Papert [2] to point to a few names.
[0]https://www.youtube.com/watch?v=oUaOucZRlmE
[2]https://www.google.com/books/edition/Mindstorms/nDjRDwAAQBAJ...
Some sources
> Math & motion: – The Nature of Code https://natureofcode.com/ – Coding Math https://www.youtube.com/user/codingmath
> Shaders / math-based rendering: – The Book of Shaders https://thebookofshaders.com/ – Inigo Quilez https://iquilezles.org/
> Interactive explanations: – Red Blob Games https://www.redblobgames.com/
You can also find some insight into his work process here: https://x.com/BCiechanowski/status/1387827101294686210?s=20
Most people doing this level of work built their own tools over time, learned a bit here and there, and kept refining things throughout their career.
You could still keep Three.js for bits like vector calculations, but it just doesn’t feel worth it, it’s easy enough to implement yourself—or copy and paste from some such library and modify as needed—and will be much lighter. And you build up the bits and pieces you need over time.
This part of the demo illustrates the point vs area light issue really well. In designing practical 3d scenes and selecting tools, we would often prefer to use 2d area or 3d volumetric lights over point lights. Difficult problems like hard shadows and hotspots in reflection probes are magically resolved if we can afford to use these options. Unfortunately, in many realtime scenarios you cannot get access to high quality area or volumetric lighting without resorting to baking lightmaps (static objects only; lots of iteration delay) or nasty things like temporal antialiasing.
One issue with modern ReSTIR path tracing is that currently the algorithm relies on white (random) noise, which contains low-frequency (large-scale) noise, which produces blotchy boiling artifacts at low sample counts. Optimally an algorithm should use some form of spatio-temporal blue noise with exponential decay to only get evenly distributed high frequency samples. But that's still an open research problem.
I've pulled some tricks like "object-pre-pufficiation" (low-frequency model manifold encapsulation, then following the same bones for deformation) mixed with normal recording in shadow layers (for realtime work on old mobile hardware), but, these days, so much can be done with sampling and proper ray-tracing, the old tricks are more novelty than necessary.
It still pays to fake it, though.
fdeage•1mo ago
phailhaus•1mo ago