Hello everyone,
I am trying to create an animation where some objects are pushed and dragged by a liquid. I'm not clear on how I should set up the DOP network and how to make the particles interact with the rigid bodies reciprocally. Could you give me some pointers or some links to docs/tutorials?
I searched the net, but I couldn't find this information.
Thank you.

Maybe this setup can help.
https://forums.odforce.net/topic/52705-help-with-floating-rbd-objects-on-flip-sim/?do=findComment&comment=240207 [forums.odforce.net]

Thank you very much, but i need to have a lot of small objects (about 200) interacting with the flip fluid and it seems that the setup in the link is good for few rbd objects...
I need to have a lot of small pieces of debris being pushed and pulled by a viscous liquid...
Thanks

the key is to use old RBD Solver instead of Bullet

for old RBD Solver if you want to create many rbd objects with one node use RBD Fractured Object it will by default use s@name attribute to split the geo into objects

Thank you Tamte,
i wasn't clear, the problem is that the pieces are not generic debris, but instances of small objects.
Unfortunately, I cannot provide many details about the scene due to a confidentiality agreement (NDA), but technically it's like having to animate a liquid that moves hundreds of small "Lego" bricks of different shapes and colors.
Something like the image i'm sharing
Thank you

combine files and methods from CGworld Japan

I don't see a reason why wouldn't you be able to use RBD Fractured Object with them, the name may be deceiving but it can be any geo with pieces defined by name attribute, doesn't have to come from fracturing

Alternatively you could also use Vellum to simulate both, liquid and rbd pieces, depending on whether it suits your project

cncverkstad
combine files and methods from CGworld Japan

Thank you, i'll search for it.

tamte
I don't see a reason why wouldn't you be able to use RBD Fractured Object with them, the name may be deceiving but it can be any geo with pieces defined by name attribute, doesn't have to come from fracturing

Alternatively you could also use Vellum to simulate both, liquid and rbd pieces, depending on whether it suits your project

Hi Tamte,
thank you, didn't know i could use any type of objects with the "RBD Fractured Object".
Could you give more details about this? I would be really grateful to you.
Thanks

Hey deremis, you'll be able to find some help here:
https://www.sidefx.com/tutorials/legoize-geometry-and-rbd-simulation/ [www.sidefx.com]

And here for the vellum fluids part:
https://www.sidefx.com/tutorials/h19-vellum-fluids-starter-pack/ [www.sidefx.com]

Cheers,

Thank you all for your precious infos

Hi all,
I've been attempting to make RBD objects interact with FLIP fluid by using the RBD Fractured Objects, but unfortunately, I'm unable to get it to work properly.
While the FLIP fluid is colliding with the RBD objects, the RBD objects themselves aren't moving.
Could someone kindly take a moment to review this setup?
Your assistance would be greatly appreciated.
Thank you.

deremis
While the FLIP fluid is colliding with the RBD objects, the RBD objects themselves aren't moving.
Could someone kindly take a moment to review this setup?

1. your fluid resolution is low relatively to the sizes of the rbd pieces
look at the Collision guide in your flipobject1
so
- set it to at least to 0.01 which would make the grid res 0.02 which would start making some effect
- or use separate collision separation that will capture the resolution of your pieces
- or make your pieces larger

2. your fluid density is 1 while rbd 1000, so the fluid has barely any effect
set your fluid density to default 1000 and rbd can stay or can be more or less depending on if you want it to float or sink

tamte

deremis
While the FLIP fluid is colliding with the RBD objects, the RBD objects themselves aren't moving.
Could someone kindly take a moment to review this setup?

1. your fluid resolution is low relatively to the sizes of the rbd pieces
look at the Collision guide in your flipobject1
so
- set it to at least to 0.01 which would make the grid res 0.02 which would start making some effect
- or use separate collision separation that will capture the resolution of your pieces
- or make your pieces larger

2. your fluid density is 1 while rbd 1000, so the fluid has barely any effect
set your fluid density to default 1000 and rbd can stay or can be more or less depending on if you want it to float or sink

Dear Tomas, I have a question. If we use the old RBD Sim for interaction with FLIP, how can we control RBDs like we do with the Geometry Wrangles beside the RBD packed objects?

N-G
Dear Tomas, I have a question. If we use the old RBD Sim for interaction with FLIP, how can we control RBDs like we do with the Geometry Wrangles beside the RBD packed objects?

If you use old RBD you are limited to control and workflows that old RBDs have since each piece is a DOP object directly, etc.

Its definitely a workaround just to make FLIP feedback working, and ideally SideFX would find a way to make mutual interaction of all solvers working one e day

Thank you very much for the precious tips Tomas.
May i ask you more details about this?

tamte
- or use separate collision separation that will capture the resolution of your pieces

Thanks again.

deremis
Thank you very much for the precious tips Tomas.
May i ask you more details about this?

tamte
- or use separate collision separation that will capture the resolution of your pieces

FLIP Object DOP/Properties/Collision Separation can be enabled and set to smaller (or larger) grid scale than other grids whose grid scale is Particle Separation * Grid Scale

therefore you can have lower res FLIP sim, but still have it consider higher resolution collision grid which would see more of your small colliders and can provide feedback to them