Stir is an interactive fluid simulation. Swipe the screen to stir up vortices, and be mesmerized by the ensuing perpetual swirly motion. Double tap repeatedly to dampen the whirlpools and slow things down.

Choose from a number of presets that change the simulation behaviour and rendering style, or modify the parameters individually. Some notable parameters:

'Viscosity' controls how thick the fluid is. High values evoke materials such as molasses or paint. Low values are more lively, such as ink in water. Note that viscosity goes all the way to zero, allowing perpetual swirly motion! This is in contrast to many current fluid simulations that dampen and slow quickly.

'Symmetric' constrains the fluid motion to be symmetric about the centre of the screen. This leads to kaleidoscopic flows or perhaps the motion of deep space galaxies.

The underlying physical fluid simulation is based on novel research which support the two aforementioned features. Resource consumption(CPU, memory) is relatively lightweight and should work well on a range of devices. Of course the harder you push it (a key parameter being the number and size of particles) will determine what's possible, but even modest hardware should be adequate for lower particle counts.

This is a beta release. Any feedback including bug reports and development suggestions are welcome.

Screenshots: