You can use the top surface layer of a low-resolution liquid simulation to guide a high-resolution simulation. This gives a detailed simulation of the surface, with breaking waves and so on, without the need to perform a high-resolution simulation to the full depth of the liquid. You can preview the bulk movement of liquid at low resolution, and when you are satisfied, use it to guide a high-resolution simulation for finer details.
Cache a low-resolution simulation
- Set up a low-resolution liquid simulation in the usual way. Make sure that the colliders are fairly thick (at least 4 voxels), including the object used to hold the pool of liquid in place.
- Create a cache of the low-resolution simulation. See
Work with Bifrost user caches.
Set up a guided simulation
- Start a new scene, using the same or similar control meshes (emitters, colliders, accelerators). Set up a basic low-resolution simulation.
- In the global guide properties, activate
Enable in the
Guided Simulation attribute group.
- In the
Input subgroup, activate
Simulation mode.
- Click the folder icon next to
Sim Cache Name, then browse to the directory where the low-resolution cache is stored and select any one of the voxel_liquid cache files (volume or particle).
- Optionally, adjust
Min Simulation Depth. This controls the depth of the liquid that gets simulated in world space, and may need to be adjusted depending on the scale to which the scene was modeled.
You should see a band of liquid on the top surface of the emitters, rather than to the full depth of the emitter.
- Play back, and adjust the settings as necessary (see
Adjust a Bifrost guided simulation). Use a low resolution at first (high
Master Voxel Size), and then increase the resolution once it's working satisfactorily.