This is a minimal Unity framework that lets you create flowing particles animations. It was originally developed at Dpt as part of a VR project.
Feel free to check out the WebGL demo:
https://etienne-p.github.io/UnityParticleFlow/
You can design a vector field in the Unity editor, and use it to animate a GPU particle system.
Take a look at the Demo scene for a better understanding:
The vector field is designed using nodes,
these nodes combine three behaviors (attractor, beam and twirl)
Nodes may be combined in a Path, so they behave as the control points of a spline
Once the vector field is designed, export the lookup textures that will be used to animate the particle system