Tuesday, 30 April 2013

Position Based Fluids Demonstration

Water is very difficult to simulate due to its surface tension and other dynamic properties.  Even for molecular dynamic simulations the air water interface is not so precise.  The video game industry is at the forefront of science and has helped drive computing to the cutting edge.  (Alan Turing would be proud!).  Games are approaching photorealism to the point that the movie the Matrix may be our new reality.  Water physics has been notoriously difficult to implement properly.   So what did people do?  They made a new algorithm.  
'A new fluid simulation algorithm (FSA) from PhysX appears to have made a breakthrough with its Position Based Fluids (PBF) technique that is based on the same Position Based Dynamics (PBD) framework used for simulating cloth and deformables in the PhysX SDK.
According to PhysX Info, PBD uses an "iterative solver" that allows it to "maintain incompressibility more efficiently than traditional SPH fluid solvers. It also has an artificial pressure term which improves particle distribution and creates nice surface tension-like effects (note the filaments in the splashes). Finally, vorticity confinement is used to allow the user to inject energy back to the fluid."
Further information on the technology is available in the following SIGGRAPH 2013 paperby Miles Macklin and Matthias Mueller-Fischer. The demonstration video (running on a single GTX 580) is available below.' via Toms Hardware.

Sounds legit.  Sound awesome.  Sounds like we are going into the Matrix.