Cinema 4D XL's built-in particles offer some interesting methods for faking certain types of effects. One such treatment is cohesion - of the attraction of particles to one another. This sort of effect is used to create ropy, stringy steam trails and various types of turbulent treatments seen in nature. It occured to me, very early in the morning as I lay awake in bed, that it might be possible to fake this dynamic effect through the careful use of attractor and friction fields objects.

The trick is to animate the fields so that they move along with the flow of particles. In this manner you use the attractor and friction fields to pull the and particles around and create whorls and stringy trails. By parenting the fields to a null object you can then use a vibrate track jostle and wiggle the fields as they rise, adding a further layer of randomness to the motion. Hand animating this sort of motion can be very tedious and would most likely have an artificial quality to it. By also adding a looping parameter track you can also add variation to the degree of influence that the fields apply to the animation. If you get a series of these all rising, wiggling, and modifying a stream of particles you can start to create a nice cohesion treatment to your particle system. In this case there are four separate attractor and friction fields influencing this example.