Dear Fellow Scholars, this is Two Minute Papers
with Dr. Károly Zsolnai-Fehér. Through the power of computer graphics research
works, today, it is possible to simulate honey coiling, water flow with debris, or even get
a neural network to look at these simulations and learn how to continue them! Now, if we look under the hood, we see that
not all, but many of these simulations contain particles. And our task is to simulate the pressure,
velocity, and other physical quantities for these particles and create a surface where
we can watch the evolution of their movement. Once again, the simulations are typically
based on particles. But not this new technique. Look. It takes a coarse simulation, well, this one
is not too exciting. So why are we looking at this? Well, look! Whoa! The new method can add these crispy, high-frequency
details to it. And the result is an absolutely beautiful
simulation. And it does not use millions and millions
of particles to get this done. In fact, it does not use any particles at
all! Instead, it uses wave curves. These are curve-shaped wave-packets that can
enrich a coarse wave simulation and improve it a great deal to create a really detailed,
crisp output. And it gets even better, because these wave
curves can be applied as a simple post processing step. What this means is that the workflow what
you saw here really works like that. When we have a coarse simulation that is already
done, and we are not happy with it, with many other existing methods, it is time to simulate
the whole thing again from scratch, but not here. With this one, we can just add all this detail
to an already existing simulation. Wow. Loving it. Note that the surface of the fluid is made
opaque so that we can get a better view of the waves. Of course, the final simulations that we get
for production use are transparent, like the one you see here. Now, another interesting detail is that that
the execution time is linear with respect to the curve points. So what does that mean? Well, let’s have a look together. In the first scenario, we get a low-quality
underlying simulation, and we add a 100 thousand wave curves. This takes approximately 10 seconds and looks
like this. This already greatly enhanced the quality
of the results, but we can decide to add more. So, first case, a 100k wave curves, in 10-ish
seconds. Now comes the linear part - if we decide that
we are yearning for a little more, we can run 200k wave curves, and the execution time
will be 20-ish seconds. It looks like this. Better, we’re getting there! And for a 400k wave curves, 40-ish seconds,
and for 800k curves, yes, you guessed it right, 80-ish seconds. Double the number of curves, double the execution
time. This is what the linear scaling part means. Now, of course, not even this technique is
perfect. The post-processing nature of the method means
that it can enrich the underlying simulation a great deal, but, it cannot add changes that
are too intrusive to it. It can only add small waves relative to the
size of the fluid domain. But even with these, the value proposition
of this paper is just out of this world. So, from now on, if we have a relatively poor
quality fluid simulation that we abandoned years ago, we don’t need to despair. What we need is to harness the power of wave
curves. Thanks for watching and for your generous
support, and I'll see you next time!
