I am trying to create a water simulation on a hexagonal platform. I am using the add-on Flip Fluid v1.1.0 Demo. I assign functions to all objects of the scene. Obstacle, Fluid, Domain. After baking, water flows through the obstacle. I assigned the physics Rigid Body to the obstacle. The result is similar. Is there anything I can do to keep the water on top of the obstacle? Or is this not possible for this add-on? I have a similar result when using MantaFlow. Blender version 2.92, 2.93.
The main issue that is causing leakage is that the obstacle object contains non-manifold geometry:
For objects to work correctly in the simulator, the geometry must be manifold/closed/watertight (Documentation).
The next issue that you will run into is that liquid will leak through thin walls at low resolutions. You can increase resolution to fix this, but this may increase simulation bake time significantly depending on how thin the obstacle is (Documentation and Solutions).
An alternative solution to increasing resolution could be to remodel the simulation setup to prevent any leakage at low resolutions:
- Create a simple 6 sided cylinder. This will be the container for the liquid.
- Set this object to an obstacle and enable the Inverse option. This will enable the obstacle to contain liquid inside of it and no liquid will be able to escape the object.
- Create a cube and model a sloped ramp to match the original hexagon container. Set this object to an obstacle.
Your original objects can still be used for rendering while these new objects can be used just for the simulation.
Hope this helps!