# The Forgotten Research That Fixed The Worst Physics Bug! ## Метаданные - **Канал:** Two Minute Papers - **YouTube:** https://www.youtube.com/watch?v=4X5T2eeG7iw - **Дата:** 03.08.2025 - **Длительность:** 5:39 - **Просмотры:** 172,427 ## Описание ❤️ Check out Lambda here and sign up for their GPU Cloud: https://lambda.ai/papers Guide for using DeepSeek on Lambda: https://docs.lambdalabs.com/education/large-language-models/deepseek-r1-ollama/?utm_source=two-minute-papers&utm_campaign=relevant-videos&utm_medium=video 📝 The paper is available here: https://graphics.cs.utah.edu/research/projects/merging-and-splitting/ 📝 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 Video game glitch: https://www.youtube.com/watch?v=fZgRVatBXTE 🙏 We would like to thank our generous Patreon supporters who make Two Minute Papers possible: Benji Rabhan, B Shang, Christian Ahlin, Gordon Child, John Le, Juan Benet, Kyle Davis, Loyal Alchemist, Lukas Biewald, Michael Tedder, Owen Skarpness, Richard Sundvall, Steef, Sven Pfiffner, Taras Bobrovytsky, Thomas Krcmar, Tybie Fitzhugh, Ueli Gallizzi If you wish to appear here or pick up other perks, click here: https://www.patreon.com/TwoMinutePapers My research: https://cg.tuwien.ac.at/~zsolnai/ X/Twitter: https://twitter.com/twominutepapers Thumbnail design: Felícia Zsolnai-Fehér - http://felicia.hu ## Содержание ### [0:00](https://www.youtube.com/watch?v=4X5T2eeG7iw) Segment 1 (00:00 - 05:00) This is a forgotten research paper, and it’s a  bit like two angry goats agreeing to wear one   oversized sweater for a second so they stop  butting heads. Okay-okay, let me explain. This is Particle Merging-and-Splitting, a  forgotten research work that almost nobody   is talking about. And it can create all  of these magical physics simulations where   things smash into each other, things crumble,  and more. Wow! Can’t believe I missed it too!    But one of you Fellow Scholars found it,  wanted to hear about it, and of course,   your wish is my command. And if you stay for  a bit longer, I’ll show you the whole footage,   we’re also going to shatter a lot of  things, and I’ll tell you how it works. Now let’s try to create realistic  physics simulations of the world,   and then…no…no…no! Please don’t do this to me.   This is the intersection bug that still haunts so   many video games and computer graphics systems.   It’s been way too long now, enough if enough. And they found that all previous  systems have this issue,   it just depends on which case we are  looking at. No perfect solution. Ouch. So…why? What is going on here? Well, common  solid-solid collision handling techniques   are based on force and impulse formulations and  these fail at resolving these kinds of collisions.   Now check out this new technique. If we  do it with low velocity…correct, and now,   the harder experiment, higher velocity: oh  my, this still works! Absolutely amazing. Now, let’s try solid-fluid collisions.    Uh-oh. Same problem with previous techniques. So,  can the new technique help here? Once again, yes! But let’s do some fracturing! I bet  that it won’t help here. With one   previous technique, oof. That’s rough. Let’s  forget this ever happened. Next technique,   this is a bit of a milder case, but it doesn’t  make any physical sense. Third technique. Wow,   this might be even more violent than the  first. Okay, so why does this happen? Well,   fracture simulations are super sensitive,  so much so that if just one particle is   much faster than the others, it can cause  the whole object to instantly crumble. Now, hold on to your papers Fellow Scholars for  the new technique: now we’re talking. Look at   that beauty! Another important problem solved.   So, how does all this black magic work? How is   this even possible? Dear Fellow Scholars, this is  Two Minute Papers with Dr. Károly Zsolnai-Fehér. The brilliant insight of the researchers is to  treat a collision not as an instantaneous event,   but as a process that takes  a small amount of time.   Imagine two speeding roller skaters that are  about to crash. And instead of bouncing off of   each other, look! They grab each other and keep  skating as a single, heavier skater. And later,   they can separate easily. This is  what particles do in this simulation. To be more precise, when particles touch  we merge them into one “meta-particle” for   exactly one time step, storing any lost kinetic  energy like compressing a tiny virtual spring   between them. After integration we split them  again, returning that stored energy. And bam!    Finally! No crazy explosions and intersections  can happen anymore. And, it gets better:   this temporary “handshake” also lets completely  different simulators, solids, fluids, fractures   exchange information robustly. So that is why  we merged these silly goats with the sweater. So, let’s pop the question: how fast is it? Let’s  see…wow, goodness! The splitting and merging   typically takes in the order of milliseconds.   Lightning-fast. Except this one. You would need   this incredibly detailed simulation for it to  even break a sweat. One word on limitations, it’s   not just one merging and splitting step, a fully  robust implementation may double the simulation   time. Totally worth it, but I wanted to point it  out. Once again, genius work that almost no one is   talking about. Except here on Two Minute Papers.   And while we look at the full footage here,   once again, it is incredibly hard to get Youtube  to recommend this kind of content, but if every   single one of you Fellow Scholars would press  like and leave a kind comment, we could finally   do more of this. We just tried it together and  it worked. I had so much fun making this, people ### [5:00](https://www.youtube.com/watch?v=4X5T2eeG7iw&t=300s) Segment 2 (05:00 - 05:00) need to hear more about forgotten works like this,  and if you help us out, you will get more of this. --- *Источник: https://ekstraktznaniy.ru/video/12213*