How Neighbor Grid3D / Grid2D Collection / SimulationStage works in Niagara?

I’m looking for a method to let particles interact with each other in Niagara, for example collision or fluid simulation. I know in UE4.25 can achieve this. Like this video below:

I guess the general workflow is use Neighbor Grid3D find nearby particles, or store their data in Grid2D, than use simulationStage or HLSL to loop these data in each particle stage calculation.

But I tried with Neighbor Grid3D and Grid2D, I have no idea how to let this run.
Is there any doc or examples to explain how Neighbor Grid3D or Grid2D Collection or SimulationStage works in Niagara? Anything about these.

I’m trying to put it all together as well. Any luck for you so far? Iv’e only tried the grid2d and simulation stage so far and get as far as rendering the grid to a texture (which fails). I dont think I’m properly setting the grid values or something. But yeah it seems theres no info out there on this stuff right now.

I’m still confused. Its so hard to understand Grid2d and neighbor grid3d .
Please if you figured out something about these share with us

I dont really think its in a ready state in 4.25. I see lots of active development of this stuff on the master branch on github in preparation for 4.26.

I have tried the master branch a number of times in recent weeks. Sometimes some stuff works, but I dont think everything is done yet. 2.5 and 3D stuff is currently hidden as far as I know, but there was a period some weeks ago when I could still see some 2.5D examples.

Some stuff can still be found within the ShallowWater plugin, but more recently they have now added an experimental plugin called NiagaraSimulationStages.

And within that plugin there are a few systems included that I can get working at this stage.

For example, when you have the show engine and show plugin content flags ticked in the content browser, there are some Flip Systems to be found. I was certainly able to get the one called Flip_System working by dragging it into a scene, and it is to be found at /NiagaraSimulationStages Content/Templates/Liquid/2D/Emitters/