Sand-like properties

[josemendez]

Thanks you for the insight!

What if I would only want to simulate moving (by magic means) sand and any resting or static sand would be simulated by other methods.
Very thin dust and smoke would be simulated by particles sprites

Would could I use obi to approach the look and feel of falling and floating sand? I suposse that's the question. 

Falling/floating sand grains do not interact/collide much with each other, or at least their interaction does not have any contribution to the overall look. So at this point, it doesn't make sense to use Obi. It would be far cheaper to use particles that do not interact with each other in any way, which is what 99% of games do for sand. You can use Unity's built-in particle system or VFX graph if you need thousands of particles. Using curl noise to make them flow around in a "magic" way (kinda like Gaara controlling sand) is cheap and looks cool.

For piling sand, the usual approach is to count how many particles hit the ground and either create a "pile" mesh that grows as more particles hit the ground  (or, if you have a terrain-like height map, just increase the height at the impact point). This is dirt cheap (no pun intended) and it looks convincing enough for most purposes. Most earth-moving simulators, both game-like and professional ones, use this combination of simple particles+heightmaps to simulate piling sand:
https://youtu.be/wrYa4JPXoAA?t=38
https://youtu.be/lq1vSduBeMc?t=130
https://youtu.be/4ZaBQHNU1WI?t=97

In the third video, you can briefly see Obi granular particles being used during excavation, since the requirement was to have large-ish rocks more than fine sand.

Also can I use ObiFluidRenderer with granular blueprints? I think I can't because the project crash 

You should be able to, the fluid renderer just takes particles as input and doesn't care about the type of particles as it only uses their shape and color. I've tried this and it works ok, could you post your crash log?