# Burning Down Virtual Trees... In Real Time! 🌲🔥

## Метаданные

- **Канал:** Two Minute Papers
- **YouTube:** https://www.youtube.com/watch?v=2jwVDRKKDME
- **Дата:** 04.05.2021
- **Длительность:** 6:20
- **Просмотры:** 126,317
- **Источник:** https://ekstraktznaniy.ru/video/13920

## Описание

❤️ Check out Weights & Biases and sign up for a free demo here: https://www.wandb.com/papers 
❤️ Their mentioned post is available here: https://wandb.ai/authors/adv-dl/reports/An-Introduction-to-Adversarial-Examples-in-Deep-Learning--VmlldzoyMTQwODM

📝 The paper "Interactive Wood Combustion for Botanical Tree Models" is available here:
https://repository.kaust.edu.sa/bitstream/10754/626814/1/a197-pirk.pdf
https://github.com/art049/InteractiveWoodCombustion

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## Транскрипт

### <Untitled Chapter 1> []

Dear Fellow Scholars, this is Two Minute Papers with Dr. Károly Zsolnai-Fehér. Today we are going to burn some virtual trees down. This is a fantastic computer graphics paper from four years ago. I ask you to hold on to your papers immediately, and do not get surprised if it spontaneously lights on fire. Yes, this work is about simulating wood combustion, and it is one of my favorite kinds of papers that takes an extremely narrow task, and absolutely nails it. Everything we can possibly ask for from such a simulation is there. Each leaf has its own individual mass and area, they burn individually, transfer heat to their surroundings, and finally, branches bend, and, look can eventually even break in this process. If we look under the hood, we see that these trees are defined as a system of connected

### Particle-based Tree Representation [0:55]

particles embedded within a physics simulator. These particles have their own properties, for instance, you see the temperature changes here at different regions of the tree as the fire gradually consumes it. Now if you have been holding on to your papers, now, squeeze that paper and look. What do you think - is this fire movement pre-programmed?

### Flame Propagation Behavior [1:21]

It doesn’t seem like it. This seems more like some real-time mouse movement, which is great news indeed, and, yes, that means that this simulation, and all the interactions we can do with it runs in real time. Here is a list of the many quantities it can simulate, oh my goodness! There is so much yummy physics here I don’t even know where to start. Let’s pick the water content here and see how changing it would look. This is a tree with a lower water content, it catches fire rather easily, and now, let’s

### Water Content and Charing Behavior [1:59]

pour some rain on it. Then, afterwards, look, it becomes much more difficult to light on fire and emits huge plumes of dense, dense smoke. Beautiful. And, we can even play with these parameters in real time.

### Parameter Space [2:20]

We can also have a ton of fun by choosing non-physical parameters for the breaking coefficient, which, of course, can lead to the tree suddenly falling apart in a non-physical way. The cool thing here is that we can either set these parameters to physically plausible values and get a really realistic simulation, or, we can choose to bend reality in directions that are in line with our artistic vision. How cool is that? I could play with this all day. So, as an experienced Scholar, you ask, okay, this looks great, but how good are these simulations, really? Are they just good enough to fool the untrained eye, or are they indeed close to reality? I hope you know what’s coming. Because what is coming is my favorite part in all simulation research, and that is when we let reality be our judge and compare the simulation to that. This is a piece of real footage of a piece of burning wood, and this is the simulation.

### Evaluation: Visual Comparison [3:24]

Well, we see that the resolution of the fire simulation was a little limited, it was four years ago after all, however, it runs very similarly to the real life footage. Bravo! And all this was done in 2017. What a time to be alive! But we are not even close to be done yet, this paper teaches us one more important lesson. After publishing such an incredible work, it was accepted to SIGGRAPH ASIA 2017. That is one of the most prestigious conferences in this research field, getting a paper accepted here is equivalent to winning the olympic gold medal of computer graphics research. So with that, we would expect that the authors now revel in eternal glory. Right? Well, let’s see. What? Is this serious? The original video was seen by less than a thousand people online. How can that be? And the paper was referred to only ten times by other works in these four years. Now, you see, that is not so bad in computer graphics at all, it is an order, maybe even orders of magnitude smaller field than machine learning, but I think this is an excellent demonstration of why I started this series. And it is because I get so excited by these incredible human achievements, and I feel that they deserve a little more love than they are given, and of course, these are so amazing, everybody has to know about them. Happy to have you Fellow Scholars watching this and celebrating these papers with me for more than 500 episodes now. Thank you so much, it is a true honor to have such an amazing and receptive audience. Thanks for watching and for your generous support, and I'll see you next time!