Dear Fellow Scholars, this is Two Minute Papers
with Dr. Károly Zsolnai-Fehér. Yes, you see it correctly, this is a paper
on paper. The paper-paper if you will. And today, you will witness some amazing works
in the domain of computer graphics and physics simulations. There is so much progress in this area. For instance, we can simulate honey coiling,
baking and melting, bouncy jelly and many related phenomena. And none of these techniques use any machine
learning, these are all good old-fashined handcrafted algorithms. And using these, we can even simulate stretching
and compression, to the point that muscle movement simulations are possible. When attaching the muscles to bones, as we
move the character, the muscles move and contract accurately. What’s more, this work can even perform
muscle growth simulations. So, are we done here? Did these ingenious computer graphics researchers
max out physics simulations, where there is nothing else to do? Oh no, of course not! Look, this footage is from an earlier graphics
paper that simulates viscosity and melting fluids, and what I would like you to look
at here is not what it does, but what it doesn’t do. It starts melting these Armadillos beautifully,
however, what there is something that it doesn’t do, which is, mixing. The materials start separate, and remain separate. Can we improve upon that somehow? Well, this new paper promises that and so
much more that it truly makes my head spin. For instance, it can simulate hyperelastic,
elastoplastic, viscous, fracturing and multiphase coupling behaviors, and most importantly,
all of these can be simulated within the same framework. Not one paper for each behavior, one paper
that can do all of these. That is absolutely insane. What does all that mean? Well, I say, let’s see them all right now
through 5 super fun experiments. Experiment number one. Wet papers. As you see, this technique handles the ball
of water. Okay, we’ve seen that before. And what else? Well, it handles the paper too, okay, that’s
getting better, but, hold on to your papers, and look, it also handles the water’s interaction
with the paper. Now we’re talking! And careful with holding on to that paper,
because if you do it correctly, this might happen. As you see, the arguments contained within
this paper really hold water. Experiment number two, fracturing. As you know, most computer graphics papers
on physics simulation contain creative solutions to destroying Armadillos in the most spectacular
fashion. This work, is, of course, no different. Yum. Experiment number three. Dissolution. Here, we take a glass of water, add some starch
powder, it starts piling up, and then, slowly starts to dissolve. And note that the water itself also becomes
stickier during the process. Number four. Dipping. We first take a piece of biscuit, and dip
it into the water. Note that the coupling works correctly here,
in other words, the water now moves, but what is even better is that the biscuit started
absorbing some of that water. And now, when we rip it apart, oh yes. Excellent! And as a light transport researcher by trade,
I love watching the shape of the biscuits distorted here due to the refraction of the
water. This is a beautiful demonstration of that
phenomenon. And, number five. The dog! What kind of dog you ask? Well, this virtual dog gets a big splash of
water, starts shaking it off, and manages to get rid of most of it. But only most of it. And it can do all of these, using one algorithm. Not one per each of these beautiful phenomena,
one technique can perform all of these. That is absolutely amazing. But it does not stop there, it can also simulate
snow, and it not only does it well, but it does that swiftly. How swiftly? It simulated this a bit faster than one frame
per second. The starch powder experiment was about one
minute per frame, and the slowest example was the dog shaking off the ball of water. The main reason for this is that it required
near a quarter million particles of water and for hair, and when the algorithm computes
these interactions between them, it can only advance the time in very small increments. It has to do this a hundred thousand times
for each second of footage that you see here. Based on how much computation there is to
do, that is really, really fast. And, don’t forget that the First Law Of
Papers says that research is a process. Do not look at where we are, look at where
we will be two more papers down the line. And even now, the generality of this system
is truly something to behold. Congratulations to the authors on this amazing
paper. What a time to be alive! So, if you wish to read a beautifully written
paper today that does not dissolve in your hands, I highly recommend this one. Thanks for watching and for your generous
support, and I'll see you next time!
