Particles interacting via Fields

CS 493 Lecture, Dr. Lawlor

A common style in physics and simulation is a set of particles, that interact via a force field.  Sometimes the particles are actual discrete objects, like moose or electrons; but often the particles are just a convenient way to discretize some finer material, like chunks of a galaxy or bullet.

Interaction / Force
Semiconductor current flow
electromagnetic field
Cosmological dynamics
chunks of galaxy
gravitational field
Meshless metal deformation
chunks of bullet
mechanical forces
Fluid dynamics (SPH)
smoothed fluid parcels
hydrodynamics (navier-stokes)
Ecological simulation
moose and wolves
predator visibility field

In each of these cases, there are several ways to calculate the field-particle interactions:
Here's a short, typical mechanical engineering paper on mesh-free metal deformation, with a giant bullet-like object smashing into a flat armor-like object:

There's a beautiful PhysX (CUDA) fluid library based on particles, with amazing video, but few technical details shown here:

Here's a 2D game engine based on fluids simulated via particles.  They adjust the size of a particle based on nearby particle density, and render the mass onscreen using a splat-and-threshold technique: