Monday, April 22nd, 2013 Posted by Jim Thacker

Video: Position Based Fluids in PhysX has posted an interesting new tech demo showing liquid simulation in PhysX via Postion Based Dynamics, the same framework PhysX uses for cloth and object deformation.

According to the accompanying description: “Because PBD uses an iterative solver, it can maintain incompressibility more efficiently than traditional SPH [Smoothed Particle Hydrodynamics] fluid solvers.

“It also has an artificial pressure term which improves particle distribution and creates nice surface tension-like effects. Finally, vorticity confinement is used to allow the user to inject energy back to the fluid.”

There are one or two quirks: for our money, the liquid sometimes looks too viscous to be water (presumably, the surface tension-like effects are slightly too strong), and the spray above the liquid surface too diffuse – but if you focus on the overall motion, the result is some pretty convincing real-time water.

Coming soon to Autodesk software near you?
The second half of the demo uses the set-up from Nvidia’s GDC 2013 demo, which also shows real-time fracturing and PhysX’s improved SPH solver. notes that it expects the technology to be included in future versions of the PhysX SDK – and by extension, software packages that support PhysX, including 3ds Max, Maya and Softimage.

Read more about Position Based Fluids on