HN Theater @HNTheaterMonth

The best talks and videos of Hacker News.

Hacker News Comments on
How Ray Tracing (Modern CGI) Works And How To Do It 600x Faster

Josh's Channel · Youtube · 170 HN points · 1 HN comments
HN Theater has aggregated all Hacker News stories and comments that mention Josh's Channel's video "How Ray Tracing (Modern CGI) Works And How To Do It 600x Faster".
Youtube Summary
In which we explore ray tracing, the reason modern CGI can look so convincing, and ReSTIR, a recent technique that allows images (and particularly animations) to be rendered hundreds of times faster.

RIS Paper: https://diglib.eg.org/bitstream/handle/10.2312/EGWR.EGSR05.139-146/139-146.pdf?sequence=1&isAllowed=y
RIS Thesis: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=1662&context=etd
Original ReSTIR Paper: https://cdn.pharr.org/ReSTIR.pdf
ReSTIR for Global Illumination Paper: https://d1qx31qr3h6wln.cloudfront.net/publications/ReSTIR%20GI.pdf

Music:
Dreamwalking by | e s c p |
Cyber Crime Story by | e s c p |
Downtown Walk by | e s c p |
I Miss You Southern Winds by | e s c p |
Kyoto by | e s c p |
Mystventure by | e s c p |
Kinetics by | e s c p |
Rain, Book, And Cup Of Tea by | e s c p |
https://escp-music.bandcamp.com
Music promoted by https://www.free-stock-music.com
Attribution 4.0 International (CC BY 4.0)
https://creativecommons.org/licenses/by/4.0/

#some2
HN Theater Rankings

Hacker News Stories and Comments

All the comments and stories posted to Hacker News that reference this video.
Oct 08, 2022 · 168 points, 16 comments · submitted by nikolay
nayuki
Another video in #SoME2 about ray tracing: https://www.youtube.com/watch?v=hCdqapTI63k
dom96
This is an amazingly well presented video.
pbohun
That was a well explained video. Thanks for the share.
wiz21c
really good video that updated my knowledge from thirty years old to 15 years old. All the probabilistic modelling is really cool!
oblak
Faster as in having something newer than Quake 2 run with 120 on modern hardware?

By the time we have ray/path traced global illumination in a $current_year game, all of my hair would be white

tuvan
A lot of current games use ray tracing as an addition to classical rasterization but NVIDIA Racer X[1] is a new tech demo/game that doesn't use any pre-baking. It's not a "real game" released by a game studio but it proves hardware is strong enough for completely simulated lighting if utilized correctly.

[1] https://www.youtube.com/watch?v=GBYs4y1BtGg

oblak
Really? That is a carefully directed video with a cool audio track. Have you tried running the actual tech demo?
atoav
I would not be that sure about that (although, admittedly I don't know the state of your hair, so maybe the timespan till all your hair is white is shorter than one might guess?)

Very basic geometry renders with all bells and whistles (refraction, reflection, complex normals, sheen effect, global illumination with both refractive and reflective caustics) in sub 2 seconds in the latest blender builds on a somewhat decent laptop with a RTX2080. The same thing would have rendered for a good minute on a decent machine a few years back.

And Blender is not even meant to do that realtime as it is not a game engine (anymore). So sure, going from 1.5 seconds to 1/60 seconds is a huge step, but similar steps have been made in a decade.

oblak
I am just that annoying guy trying to remind everyone Q2 RTX is still the best we've got in terms of actual games. Take that at face value. It barely runs on ~6 year old gpu.

I was about to pull a few numbers out of my ass as to how it must on a 3090 but then I thought someone on youtube must've done it already. And they have[0]. 52 fps is not great. I am no game maker of any kind but even my non-pro eyes can tell modern titles have way more geometry so the best we've got out of them is shiny surfaces and fake GI like in Metro.

[0] https://www.youtube.com/watch?v=dVS2zwqeUaU

That said, I am eager to get my hands on that mythical ray traced RTCW someone at AMD has been working on.

fl0wenol
Honest to goodness the results don't seem worth it for the power usage. Pre-baked lighting, environment maps, material shaders look _really good_ and are easy to get decent frame rates out of without sacrificing artistic freedom. Why are we making it more difficult for ourselves with global illumination which just introduces more problems. It's just very difficult to realistically light things while still maintaining high-visibilty of game assets in dynamic situations.

It sells graphics cards but I just don't think it's very practical.

mrshadowgoose
My condolences for the imminent loss of hair color.
oblak
I am just morphing into my Targaryen form, only without the dragons and everything else that makes them special.
zokier
I thought raytraced GI was pretty unexceptional these days, Metro Exodus did that already back in 2018: https://www.youtube.com/watch?v=Ms7d-3Dprio
oblak
Yes, ray traced GI in Metro was pretty unimpressive.
Veedrac
Global illumination is a very broad topic, and there are many different implementations at different levels of approximation.

Metro Exodus used one version that I think was one bounce only, and heavily denoised. The Enhanced Edition added probe based GI, which is infinite bounce but only captures low frequency lighting. Lumen uses surface caching, which is expensive and has low frequency temporal noise, but is higher quality yet. This video was probably covering ReSTIR GI, which is a much more advanced newer technique that has a diffuse surface approximation for multi-bounce but is otherwise almost unbiased, but might have been referring to the even newer GRIS, which can be actually fully unbiased.

So... yes and no? Some GI is unimpressive, though IMO Metro Exodus' still holds up, but the cutting-edge stuff you can only see in tech demos right now.

a1371
We know about this video and lots of indie math explainer videos like it thanks to 3Blue1Brown's "summer of math exposition". if you haven't heard about it, think of it as the best binge watch drop ever

https://youtu.be/cDofhN-RJqg

Oct 02, 2022 · 2 points, 0 comments · submitted by Tomte
The whole video is worth watching, but it is revealed in the end that the following are selected as winners, and many more are honorable mentions.

The first item in the list is a non-video contribution - an interactive story.

- Clear Crystal Conundrums https://explanaria.github.io/crystalgroups/

- This Is the Calculus They Won't Teach You https://youtu.be/5M2RWtD4EzI

- How Realistic CGI Works https://youtu.be/gsZiJeaMO48

- Percolation: a Mathematical Phase Transition https://youtu.be/a-767WnbaCQ

- The Coolest Hat Puzzle You've Probably Never Heard https://youtu.be/6hVPNONm7xw

HN Theater is an independent project and is not operated by Y Combinator or any of the video hosting platforms linked to on this site.
~ yaj@
;laksdfhjdhksalkfj more things
yahnd.com ~ Privacy Policy ~
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.