Animating an object falling into a glass of water


I’ve been trying to create an animation with an object falling into a glass of water and making a big splash. Thus far, nothing good came up with fluid simulation (I’m currently using Blender 2.91.2).

I have an extruded cylinder mesh for the water glass, a mesh for the water in the glass (which is a duplicate from some faces of the glass with a fill on the top), and a UV sphere keyframed to fall down into the glass. All within the usual domain cube covering everything. I’ve setup the sphere as an effector, the water mesh as a geometry fluid. As for the water glass itself, I didn’t know what to choose… anyway, neither seems to work.

Once it’s baked, the sphere falls into the water mesh, but then it’s just “swallowed” lifelessly by it. No splash. Diffusion and mesh are checked with default values. The number of samples of the bake does not change anything. On the other hand, if the water is not contained within another mesh, it works out fine.

I’d like to find out what I’m doing wrong. I’ve been reading books and watching tons of Youtube videos (notably this one Quick Water Simulation (2.80), but it doesn’t work the same with 2.91.2.

Thanks in advance.

For me it also did not do anything until I touched the resolution in the domain settings. It seems to be a small bug there.

I’ve also tried to play with the resolution, as I’ve also found out that for some reason, it’s the main source of problems with fluid simulation.

If I may ask, at what resolution did you start to get a satisfying result ?

Actually, I just needed to change from the 32 what was there and the thing just changed and the blue particles appeared. Then if you bring back to 32 it works, but the simulation is more like a gel or something. The reaction is really soft.

In the tests I made I started to have the splash effect on 100 on the resolution. Until 60 it was disappointing. I did not try other values.

This is what I got with resolution at 60: image

Thanks for that, that picture sure gives me hope !

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