This paper introduces a method that simulates and animates fluid as it flows through a network of tubes, with arbitrary topology, in three dimensions. The simulation computes the flow through the network, given pressure functions at one or more places. This computation is based upon Poiseuille's equation for flow through a tube, and is fashioned to preserve volume. Primarily, these significant events occur when flow either converges or diverges at junctions of the network. Such events tend to mix the fluid as it flows.
Animation correctly sequences such events.
It is separate from the simulation calculations, and so provides a general mechanism. The method is illustrated via simulated x-rays of blood flow through vessels.