 Dear Fellow Scholars, this is two-minute papers with Kato Ejona Ifehir. It has been a while now since we've talked about fluid simulations and now it is time for us to have a look at an amazing technique that creates simulations with viscoelastic fluids plus rigid and deformable bodies. This is a possibility with previous techniques that takes forever to compute and typically involves computational errors that add up over time and lead to a perceptible loss of viscoelasticity. I'll try to explain these terms and what's going on in the moment. There will be lots of eye candy to feast your eyes on throughout the video but I can assure you that this scene takes the cake. The simulation phase here took place at one frame per second which is still not yet fast enough for the much coveted real-time applications, however, is super competitive compared to previous offline techniques that could do this. So what does viscosity mean? Viscosity is the resistance of a fluid against deformation. Water has a low viscosity and rapidly takes the form of the cup we pour it into where honey, ketchup and peanut butter have a higher viscosity and are much more resistant to these external forces. Elasticity is a little less elusive concept that describes to what degree a piece of fluid behaves like elastic solids. However, viscous and elastic are not binary yes or no concepts. There is a continuum between the two and if we have the proper machinery we can create viscoelastic fluid simulations. The tau parameter that you see here controls how viscous or elastic the fluid should be and is referred to in the paper as relaxation time. As tau is increased towards infinity, the friction dominates the internal elastic forces and the polymer won't be able to recover its structure well. The opposite cases where we reduce the tau parameter to 0, then the internal elastic forces will dominate and our polymer will be more rigid. The alpha parameter stands for compliance, which describes the fluidity of the model. Using a lower alpha leads to more solid behavior and higher alpha leads to more fluid behavior. The cool thing is that as a combination of these two parameters we can produce a lot of really cool materials ranging from viscous to elastic to inviscid fluid simulations. Have a look at this honey pouring scene. Hmmm. This simulation uses more than 100,000 particles and 6 of these frames can be simulated in just one second. Wow. If we reduce the number of particles to a few tens of thousands real time human interaction with these simulations also becomes a possibility. A limitation of this technique is that most of our decisions involving the physical properties of the fluid are collapsed into the tau and alpha parameters if we are looking for more esoteric fluid models we should look elsewhere. I am hoping that since part of the algorithm runs on the graphics card the speed of this technique can be further improved in the near future. That would be awesome. Admittedly we've only been scratching the surface so make sure to have a look at the paper for more details. Thanks for watching and for your generous support. See you next time.