Fluid geometry not flowing when baked inside of domain

Question

My goal was to have the head turn into fluid and fall down onto the floor of the domain. I have done a little with fluid sims in the past. I'll try to describe everything I did, but I think downloading the blend file will make the problem/solution clearer. I started by making a cube around the head, then designating it the domain. I then took the head(split into 2 parts from a previous animation, with the bowtie being the 3rd part) and designated all parts as a geometry. After baking the fluid, I played the animation, and it didn't flow. The domain cube didn't even disappear like it usually does. I made sure that mesh was checked in the domain, set viscosity to 0, looked inside the head to see if it was full of liquid, and there was nothing. I then set the initial velocity to see if the fluid would render, rebaked it, and got nothing again. I made sure the resolution and sampling steps were high, baked it, and still got nothing.

Why isn't the head-shaped fluid showing up or flowing and why is the domain not even disappearing? Do you think it's a cache issue?

Thanks!

Answer 1

Your inflow object (head) is not closed/manifold. Close it with faces. You can retruy it yourself. Insert a simple UV Sphere, make it inflow -> works. Insert another simple UV Sphere. Delete some faces. Make it inflow -> does not work.

Answer 2

Your head is open at the top. To generate fluid particles Mantaflow needs:

either a closed mesh so that it can create the particles inside the volume

or

if you want keep an open mesh to generate particles, you have to enable the option Is Planar on the flow object, i.e. the head.