Fluid is "too heavy"/doesn't splash

Question

I'm trying to reproduce CG Geek's tutorial creating a wine glass and fluid: https://www.youtube.com/watch?v=9bZkivGauxY. While I created the wineglass on my own, I just wanted to focus on the fluid simulation, but Blender 2.9 got that Mantaflow thingy, whilst he was still baking the fluid with the old version.

My problem is that I simply can't make the water splash out of the glass. It just keeps wobbling but that's it. Does someone have an idea how to create that nice splashing effect in Mantaflow and tell me what I'm doing wrong?

Thank you in advance. Here is the link to the Blend file: https://blend-exchange.com/b/sjr35Djb

https://i.sstatic.net/GjUHe.jpg

Answer 1

I have found the solution to your problem that is pretty simple (but unfortunately can be time consuming) Luckily it doesn't require much work on your part, that's what computers are for.

Anyways, to solve your problem and make your fluid splash upwards like you want, you have to increase your resolution divisions in the fluid domain settings by a bunch (see image below)

Doing this gives the fluid much more geometry to work with, and enabling it to behave much more like a real liquid.

Here is an example render that I made, using 212 resolution divisions: As you can see, it looks much closer to your desired effect, it's not perfect, but it's pretty good looking in my opinion.

Now, the downside to doing this is that the more resolution divisions you add, the more time it will take to bake, however, if you just want a still image for your final output, I would only bake the first 50 frames and then find out which one works best for you. The image above was taken on frame 20, so it didn't take long for me.

Lastly, for some optional settings, if you want your liquid to splash up more, you can play with the gravity Z axis settings in the fluid domain settings. (see image below)

It is automatically set to 9.8, (which is about what earth's gravity is) if you make the number higher, things start to get a bit more light and floaty. the render above uses a gravity of -6 on the Z axis.

In conclusion, more resolution divisions on your fluid equals more realistic behavior, I hope this helps you!

Answer 2

Here are some steps to a splashing success:

1. Allow for a large enough interior: by setting your glass collision surface thickness to 2.0, you are effectively narrowing the interior used for the simulation (e.g., thickness beyond the glass mesh). It would be more like swilling a narrow champagne glass. a minimum of 0.5 is required. I used 0.6 just for a stab
2. For the domain I: 1) used a smaller particle radius in Liquid params (0.8) for a finer simulation and 2) used a 1.0 part radius in the mesh and 3) increased resolution from your 64 to over 100 and 4) increased sampling to 5.
3. I don't think you gave the glass much of a swill, so I increased the Y and also added an asynchonous swing to the X axis and set animation interpolation mode to linear (more of a jerk to the glass), because that's how I swill and get my wine airolating!
4. Disabled your Sphere from the render as it eclipsed the result

You may not need all 3 of these, but here it is (sim is only from frame 8 to 50):