There is now a better way to do Interparticle Collisions, pouring liquids, etc...
Use nParticles.
Check this tutorial by Duncan Brimsmead, one of the developers of Maya Fluids & the Nucleus system etc.

https://area.autodesk.com/blogs/dunca...ith_nparticles


...otherwise, fluids are the way to go.

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Just FYI:
The OLD outdated "pre-fluids" way was to do this:
https://www.highend3d.com/maya/tutori...cs_fx/213.html