Hi,

these days I'm going through many of the provided examples in the Houdini help material and I've bumped today into the “Fluid Feedback” example, which shows a ball falling onto a fluid and floating instead of sinking, thanks to the Feedback Scale parameter in the fluid solver.

I swapped the fluid object and solver with a Flip Object and Flip solver, scaled the Feedback Scale parameter in the Solver tab again but the ball doesn't float … anyone can tell me what I am doing wrong?

thanks!

without file it is difficult to tell

since if you put default FLIP Tank from shelf, set feedback scale to 1
default shelf sphere, set as RBD, move above water level
hit play, it works as expected

hmm you're right.
I wish I had my file still running but it crashed after I applied some fan force to a cloth object

thing is, (bad me), I don't use the shelf that much yet, and all I've done earlier was to load the example file from the Houdini help, and swap the fluid object and solver for the Flip ones, than change the feedback parameter and it wasn't working.. but thank you!

ah, I've found what the problem was.

The collision particles separation plays a big role in this.
by default is checked off (in the Flip Object Properties) .. I did checked it on and played with numbers:

// by setting the same separation as the fluid particle separation the ball goes through

// by multiplying it by twice the fluid particle separation, for example, it works.

but then again if I multiply that collision separation by 3 time the fluid particles separation it goes through again …
also, by changing the tank size everything changes again .. of course.

allright, I guess I need to understand better what's that collision separation

Thanks!