Dear Fellow Scholars, this is Two Minute Papers with Dr. Károly Zsolnai-Fehér.
After reading a physics textbook on the laws of fluid motion, with a little effort, we can make
a virtual world come alive by writing a computer program that contains these laws, resulting in
beautiful fluid simulations like the one you see here. The amount of detail we can simulate
with these programs is increasing every year, not only due to the fact that computer hardware
improves over time, but also, the pace of progress in computer graphics research is truly remarkable.
And, this new paper promises
detailed spiral-spectral fluid and smoke simulations. What does that mean?
It means that the simulations can be run in a torus, spheres, cylinders, you name it.
But wait, is that really new? When using traditional simulation techniques, we can just
enclose the smoke in all kinds of domain shapes where the simulation takes place.
People have done this for decades now. Here is an example of that. So, what is new here?
Well, let’s have a look at some results and hopefully, find out together.
Let’s start with the details first. This is the new technique. Hmmm.
I like this one. This is a detailed simulation, sure, I’ll give it that. But we can already create
detailed simulations with traditional techniques, so, once again, what is new here? You know what,
let’s compare it to a traditional smoke simulation technique and give it the same amount of time to
run, and see what that looks like. Wow. That is a huge difference. And, yes, believe it or not, the
two simulations run in the same amount of time. So, it creates detailed simulations. Checkmark.
And, it has not only the details, but it has other virtues too. Now, let’s bring up the heat
some more. This is a comparison to not an older, classical technique, but a spherical-spectral
technique from 2019. Let’s see how the new method fares against it. Well, they both look good,
so maybe the new method is not so much better after a…wait a second. Ouch!
The previous one blew up. And the new one,
yes, this still keeps going. Such improvement in just about two years. So, it is not only fast,
but it is robust too. That is super important for real-world use. Details and robustness. Checkmark.
Now, let’s continue with the shape of the simulation domain. Yes, we can enclose the
simulation within this domain where the spherical domain itself can be imagined as an impenetrable
wall, but it doesn’t have to be that way. Look. We can even open it up! Very good.
Okay, so it is fast, it is robust, supports crazy simulation domain shapes, and even better,
it looks detailed, but are these the right details? Is this just pleasing for the eye,
or is this really how the smoke should behave? Well, the authors tested that too,
and now, hold on to your papers, and…look! I could add the labels here, but does it really matter?
The two look almost exactly the same. Almost pixel perfect. By the way, here you go.
So, wow, the list of positives just keep on growing. But we are experienced Fellow Scholars
here, so let’s continue interrogating this method. Does it work for different viscosities? At the
risk of simplifying what is going on, the viscosity of a puff of smoke relates to how
nimble the simulation is. And, it can handle a variety of these physical parameters too.
Okay, next, can it interact with other objects too? Some techniques look great in a simple,
empty simulation domain, but break down when placed into a real scene where a lot of other
objects are moving around. Well, not this new one. That is a beautiful simulation, I love it.
So, I am getting more and more convinced with each test. So, where is the catch? What is the price
to be paid for all this? Let’s have a look. For the quality of simulations that we get,
it runs in a few seconds per frame. And it doesn’t even need your graphics card,
it runs on your processor. And even that, this is blazing fast.
And, implementing this on the graphics-card could very well put this into the real-time domain,
and boy, getting these beautiful smoke puffs in real time would be an amazing treat.
So, once again, what is the price to be paid for this? Well, have a look. Aha! There it is.
That is a steep price. Look. This needs tons of memory. Tens of gigabytes.
No wonder this was run on the processor, this is because modern consumer graphics cards
don’t have nearly as much memory on board, so what do we do? Well, don’t despair - not even
for a second. We still have good news. And the good news is that there are earlier research works
that explore compressing these datasets down, and it turns out, their size can be decreased
dramatically. A perfect direction for the next paper down the line!
And, what do you think? Let me know in the comments below what you would use this for.
And, just one or two more papers down the line, and maybe, we will get these beautiful simulations
in our virtual worlds in real time. I can’t wait. I really cannot wait. What a time to be alive!
Thanks for watching and for your generous support, and I'll see you next time!