A cheap fluid-ish simulation which runs on Mobile SDR (Quest 3) pipeline.
This uses a series of pre-baked textures to simulate particle flow down a river. The maps used in the simulation are:
Mask Map - A B/W map which is used to determine which areas are inside the river
Flow Map - A custom RT=painted flow map influnce the direction of the particles
Height Map - Allows for rivers which flow down hills, stepped rivers etc - controls how particles move over waterfalls
JumpFloodMap - Contains the distance to the nearest surface, and its direction, which lets particles collide/repel from edges\