Flip Fluid Volume Loss, Particles Dying

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Greetings,

I'm doing a basic flip simulation where I fill a cup with liquid and then I rotate the cup to spill the liquid into another cup.

Sounds super easy and basic, but after some time fine-tuning the collisions and the liquid, I can say with certainty that my liquid volume is getting less and less like my particles are dying or sucked into the geometry.



A searched a lot for a solution, like changing the Scale of the scene, or lowering the Grid-Scale ( CG Wiki ), or change the collisions but nothing really helps at all.



thank you in regards

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Volume Loss.mp4 (7.1 MB)

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Definitely looks like the fluid is leaking through the cup collisions. How are you sourcing your colliders? Have you checked the FLIP object ‘collision’ guide visualization?
You may need a higher-resolution VDB for your cups, and perhaps increased VDB bandwidth. Sometimes, checking ‘fill interior’ in the Volume collision source helps with thin objects too.
The other trick is to source a small amount of divergence into your sim to help preserve the fluid volume as the cup fills.
–Dave
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Thanks for your answer but I don't think that my liquid is leaking out, I don't see any liquid going out of the cup, and also at the beginning the fluid seems stable, but when I spot emitting and I start rotating it happens
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In my experience you won't always ‘see’ the particles leaking out. If you're using reseeding the solver will kill them if they end up inside the collision object, and the particles can also become compressed spatially without using particle separation.
Not much more I can suggest without taking a look at the .hip file, will crack it open if you post it here.
Cheers,
–Dave
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Image Not Found

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Coffee_NEW_02.hip (2.1 MB)

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and the geo I import

Attachments:
Cup_Made_By_Tyro_Smith.obj (9.2 KB)

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use collision separating
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