The Follow Path helper force pushes a fluid along a spline curve. The degree of force is controlled by a virtual pipe around the spline. For points outside the pipe, the force pushes the fluid toward the spline. For points inside the pipe, the force pushes the fluid along the spline.
To give a balance between predictability and the randomness of natural behavior, two important values are used: terminal velocity and influence. The terminal velocity is the maximum velocity a particle can reach, set by Follow Speed, Pull Speed, and Rotation Speed. The range of possible speeds can be limited to values near or at terminal velocity, or a wider range of speeds can be used, for example ranging from 1/10 of terminal velocity up to terminal velocity. The Influence parameter sets the range of possible speeds.
