Liquid Source - emits only at the bottom? (all faces set to same ID, surface force)

[Alexx31]

I was wondering a long time, why sometimes my emitter source worked and sometimes not.
It's a box, all faces have the same polygon ID.
Now I found out, that when I lift the box a bit over the ground, it emits a lot liquid, and when I put it on the ground or it even intersect, nearly no liquid comes.
I don't understand this... is there a reason, why not all faces emit?

Thanks

[Svetlin.Nikolov]

Could it be that you have any open geometries such a planes in the scene? If you do, you have to put a shell modifier on them, otherwise they will break the liquid simulaiton.

Cheers!

[Alexx31]

Thanks, yes, I have many of them!
I thought it's only concerning, if they work as colliders (and my colliders are closed geometry), but I did not know that just the existence of any open geometries inside the simulator corrupts the scene.

- In case I have an image plane placed non-solid inside the simulator, will it also corrupt the simulation?

So I'm cleaning up my scene right now, I had strange issues since weeks and maybe it's the reason.

[Svetlin.Nikolov]

Yes, either make them non-solid, or even better - exclude them from the Scene Interaction rollout to be completely sure (non-solids can still be picked in Sources as emitters of fluid, or can attract fluid via the Body Force, so the Simulator still sees them and processes them if needed).

Cheers!

[Alexx31]

Okay, good to know! I cleaned the scene, but I still have trouble, when I simulate falling water:
With 1 substep it looks right, with 2 substeps it looks totally wrong, the water has different speeds, some water seems only to move with a quarter of speed.

So I think it's still something else I don't know.

Because it's a secret project, I have forwarded a screen-recording to the support... (ticket number is: 17994)
I am fighting since days with the issue.

Many thanks

[Svetlin.Nikolov]

Thank you! We really have to see how it looks in order to figure out what's happening. Will see what the support guys and gals will find.

Cheers!