I am currently looking into building a rig for putting a object into a flowing river. now the problem is three fold.
1) the main problem is that the river is pretty damn flat, 1 degree decline max.
2) its a big area 60 meters long, 50 wide
3) the river is moving very slow
now naturally i could simply animate the collision geo against the flow at the speed i want the river to flow and then counter animating the cache post sim.
that way i would get the interaction with the object the way it should be.
now the problem is that i only get the interaction that way, and would never get the feeling of a flow in areas where there is no collision objects.
I tried a few things, sourcing new particles on one side while a continues force at the bottom of the river pushes the water.
I tried grabbing the particles that will leave the put them to the start of the container, making a infinite loop kind of tank.
The problem with all of those is that I loose water. basically the longer the sim runs the lower the water level will be.
In the end of the day I will want to be able to take a flat tank at any size and just have the water run through it at any speed with out loosing water.
If anyone has any suggest I would highly appreciate hearing about them