# Unreal Engine 5 - Ray Tracing Supercharged!

## Метаданные

- **Канал:** Two Minute Papers
- **YouTube:** https://www.youtube.com/watch?v=JYI1srodjeg
- **Дата:** 13.12.2024
- **Длительность:** 9:19
- **Просмотры:** 103,070
- **Источник:** https://ekstraktznaniy.ru/video/17218

## Описание

❤️ Check out Lambda here and sign up for their GPU Cloud: https://lambdalabs.com/papers

Try Unreal Engine 5 here:
https://www.unrealengine.com/en-US/unreal-engine-5

My free course on ray tracing for you Fellow Scholars:
https://users.cg.tuwien.ac.at/zsolnai/gfx/rendering-course/

Our earlier paper with the spheres scene:
https://users.cg.tuwien.ac.at/zsolnai/gfx/adaptive_metropolis/

LuxCoreRender (free and open source): https://luxcorerender.org/

📝 My paper on simulations that look almost like reality is available for free here:
https://rdcu.be/cWPfD 

Or this is the orig. Nature Physics link with clickable citations:
https://www.nature.com/articles/s41567-022-01788-5

🙏 We would like to thank our generous Patreon supporters who make Two Minute Papers possible:
Alex Balfanz, Alex Haro, B Shang, Benji Rabhan, Gaston Ingaramo, Gordon Child, John Le, Juan Benet, Kyle Davis, Loyal Alchemist, Lukas Biewald, Martin, Michael Albrecht, Michael Tedder, Owen Skarpness, Richard Sundvall, Tara

## Транскрипт

### Segment 1 (00:00 - 05:00) []

an absolutely huge Revolution is coming in gaming and Virtual Worlds and it is a big deal I just read something impossible here Unreal Engine 5 claims that it has realtime path tracing now hold on for a minute when they say path tracing they mean a light simulation program where we shoot rays of light into the scene bounce it around objects and depending on their geometry and materials compute what this scene would look like in reality pretty wild now it is a true miracle that we can do that at all but it has a cost a steep cost these simulations can take from minutes to hours and this earlier experiment of ours took three weeks and the help of a whole Community to compute all this for just one image although it was totally worth it I mean look at that reflected voice ometric cos stics love it so here it says real time path tracing that is insane to start with this is something that takes forever not something that you can just get in real time not even close how is that even possible and at all dear fellow Scholars this is two minute papers with Dr K now many techniques claim that they are doing some sort of R racing in real time there are hundreds of papers but most of them are really Limited in some sense one of the better ones is called voxel cone tracing one of the Blockbuster papers that can do something like that it truly changed how I look at research to this day but that one also has its limitations it cannot compute too many light bounces light can leak through objects in unexpected ways the resolution is not that great at places and so on nvidia's RTX retracing video cards are getting closer and closer which is fantastic and it truly makes a difference in some new games but depending on how you set it up glitches and unexpected results may still come out so regular offline PA tracing is very slow but very accurate look at this progress bar below it is still going for just this one frame it is slowly getting better but we still have plenty of noise in the scene and most real-time Solutions are very quick but also inaccurate but perhaps not this one hold on to your papers fellow Scholars and look same scene but with real time pass tracing at 60 frames per second absolutely amazing but wait we have three important questions question number one so what do we get with all this R tracing thing should we be excited the answer is in my opinion yes fellow Scholars this will get us a ton of value for instance it is not that sensitive to the number of Lights in the scene so you can go ham and just put a ton of Lights in there beautiful also better computations for lights indirect illumination and shadows more sophisticated material models and generally higher quality images for instance you see that with the previous Technique we have these thin beams that hit the ground M look around those there should be more light scattering around and I see none of that and when using Ray tracing let's have a look Bravo look at how creamy and beautiful that is and the whole image is also brighter but in an intelligent way so to say and the Shadows of the character are truly sight to behold the longer you look the more beautiful it is wow chef's kiss I want this everywhere and here it is and when we move lights around in a video game look at that is the incredible interplay of light and geometry that is on a different level than we've seen before like I said this kind of Shadow computation is also just amazing and this is a past traced forest in this scene H I am wondering why they uploaded this in 1080P resolution in the age of 4K and 5K monitors I would have loved to see this in all its glory and check out this scene that has all of these puzzle pieces put together I am a light transport researcher by trade so for me when I was working on my PhD these scenes took from minutes to even weeks to compute for just one image

### Segment 2 (05:00 - 09:00) [5:00]

and now to see all of these papers come alive in a system Unreal Engine that is free for most people I am truly out of words and just think about being an artist and building a virtual world where you see all of these beautiful light interactions in real time as you build the level what a joy my goodness now we have two more questions question number two how close is it to the offline version of PA tracing that takes much longer the answer is quite surprising in many cases quite close it is not exactly the same but look at those tasty glossy Reflections this one is very close and this one well not so much but the rest including the super soft Shadows on the floor seem quite good to me so now question number three so how is all this black magic possible well instead of simulating billions and billions of light rays it only simulates Millions H but how can we just do Millions instead of billions which is a thousand times less and still get this close that sounds insane to me in fact that feels flat out impossible well first it does not use Ray tracing everywhere it only uses it where it is really needed typically indirect lighting where light has bounced around at least a couple times in a diffus environment specular glossy Reflections are really good when R traced so those are better too and it builds upon a technique called rer they say it is a spatio temporal sampling technique but I hear you asking caroy what does that even mean well sampling means that we shoot a ray of light through a pixel and bounce it around in the scene and when we do that we hope to also get to know more information about its neighbors so that is spal information but it also makes use of temporal information that is the time domain what happened to this pixel just a moment ago there are also the noising algorithms tailored to Ray tracers and reer plays really nicely with them and I'll note that everything that you saw here today is Child's Play compared to what rate racing techniques are truly capable of and will be capable of in real time in the future why well because now only the topshelf hardware can do this so many games are still made not with r tracing in mind but as a nice to have addition that some people use but later when all Hardware will be able to do this then they embrace more sophistic ated incredible material models higher resolution geometry wow it will be insane just imagine that we might get these incredible scenes in our games virtual worlds just two more papers down the line go papers now because of all this if you got excited for R tracing and I mean how can you not I would like to offer you a full Master level course on how to program such a system from scratch full light transport from nothing and only today for a low price of nothing yes I give this away to all of you for free as a gift no strings attached you can't even pay for it even if you wanted check it out in the video description so what do you think what would you fellow scholar use this for let me know in the comments below to run your own experiments on an Nvidia GPU check out Lambda I use it myself regular regularly for these videos H look at that you can generate high quality images in less than a second per image I did a ton more of them and paid less than a dollar for all this crazy seriously try it out now at Lambda labs. com SLP papers or click the link in the description