After fiddling around with particle systems, I realized I couldn’t find a way of emitting particles in a reverse triangle shape (i.e. they start broad but get narrows with time). All the velocity/velocity over lifetime/force over lifetime options lead to the same result - either I could get the particle system to spread outward from its origin or make all of it trail in one specific direction. I’ve added some illustrations to make my point easier to understand.
For complicated use cases with the particle system, you might be better off manually relocating (move them around one by one, manually) the particles in your system. You could take them all in to an array, and loop through them, moving them however you see fit! For instance you could have them do shapes which aren’t built into the editor’s gui…
Here is a pile of resources to help you:
or specifically:
where you can change things like the position of a particle using:
If you haven’t already, read this stuff, great info about unity’s particle systems, and very in depth:
https://www.raywenderlich.com/113049/introduction-unity-particle-systems