Hello everyone,

I know this is a recurring topic, but I need any advice.
I have a bowl, which I scaled to about 1m radius, I thickened the bowl.
I am currently at a grid scale of 1.5 and I have a particle seperation of 0.005 / 0.004 (between 8 and 13million points)

I initialize all my rbd hero at frame 1, some on the surface and others further away so that they gradually fall into the bowl.

The rbd solver is set in bullet mode and has 25substeps
The flip solver has a feedback of 0.17 and 1/4 substeps

The first surface collisions go well, then after x impacts the water level begins to drop drastically.



I tested a lot of things,
- lower the grid scale even lower
- different substeps for the 1/10 or 2/3 flip for example
- set the rbd in rbd mode and have 4/4 substeps
- change the collision detection (particle / moving)
- add a little viscosity
- change the bowl with a cylinder
- or even limit too heavy or fast rbd by taking them out of the flip


I also saw on the forums a technique based on divergence, but in my tests it only blew the flip.

I even tried pushing with a collider from below, or emitting from the bottom, but that doesn't work besides adding time to the simulation.

Also concerning the rbd from time to time some go crazy: they react strongly to other rbd / flip

Any advice is welcome
Thanks!

Hello,

I think I have a similar problem so I will post it here. I can't find solution for volume loss in flip after introducing rbd object. I've tried everything, I knew that could help but with no luck. I'm attaching hip file, so maybe someone has some time to look at this, and push me in right direction.

Thanks!

Orsonorix
Hello,

I think I have a similar problem so I will post it here. I can't find solution for volume loss in flip after introducing rbd object. I've tried everything, I knew that could help but with no luck. I'm attaching hip file, so maybe someone has some time to look at this, and push me in right direction.

Thanks!

Hi Orsonorix, I'm facing same issue. Were you able to solve the problem?

https://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Flip [www.tokeru.com]

I can't run my computer now.
In DOP exists gas node for preserving volume.
Something like Gas Equalize Volume.
Fluid solver has two ... "things".
He add points where particle amount too small, and remove particles which stack into another particle.
Read "Reseeding" and "Separation" in fluid solver documentation