Understand the particles function

When mimicking water, or anything that behaves like a fluid, a particles system is used. The point of the system is to mimic real-world physics as close as possible, and the easiest way to understand this is to play with ping-pong balls.

Use a bowl and look carefully as they fall into the bowl. Better still, film the balls as they drop and then replay the action frame by frame to get a feel for how they move. A program’s particles system calculates a particle’s trajectory by taking into account the initial speed, rigidity and the speed of other nearby particles.

In the case of water, it also considers how many particles merge into one, which is known as smooth collisions. The odd thing here is that to calculate the collisions, a mathematical analogy of heat is used where the centre is considered hot and the contour line is drawn at a certain lower “temperature” around the particle. At a particular distance determined by this temperature, the lines of two, or more, different particles merge, making a liquid.

With this system, you can create rain, waterfalls and any other body of water. Put a boat on an ocean, a fish in the water and you can create a scene with fishermen. There are also excellent simulations available on the web and if you run Blender, a similar system with the same name is available from the Physics tab, where you can crush things and put them on fire!