TFD For Liquid Simulation

Workflow
#1

Hi.
I wonder whether it is possible/practical to adapt TFD for liquid simulations like in the video below. Because now for me it looks like it is the fastest simulation that can be made in Cinema 4D. For example, if I’d try to render animation with the same level of detail with X-Particles it would take me too much time.

Are there examples of such workflows? And is it a good idea overall?

And one question regarding this specific video:
I’ve set Dens. Diffusion & Dissipation to 0, but my smoke still disappears with time. Why it happens and how to prevent it?

#2

One fundamental difference between gaseous and liquid simulations is that gas particles effectively have no size (they are infinitely small) while liquids have a specific size. That is, pumping more smoke particles into a volume region increases the smoke density in that volume indefinitely. OTOH pumping liquid particles into a volume region will eventually fill it up such that no more liquid particles fit. At that point pushing more particles into it forces others out of the volume.
The visual difference is that gas can basically move through itself like ghosts, while liquids collide like many small rigid bodies would, forming waves and splashes.

The smoke disappearing in your sim is lack of precision in the smoke simulation method. There are mass conserving methods that prevent this at the cost of an increase in simulation time. The next major release provides one such method. However, this will not resolve the fundamental difference of gas and liquid sims.
There is however, an early prototype of an actual liquid sim. I expect to see more of it later this year.

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#3

Thank you for the detailed answer. And looking forward for the next release :slight_smile:
Also, it would be great if you could extend the simulation to the liquids as well. Because, as I mentioned, it looks like this simulation logic/plugin/algorithm is the fastest one in Cinema 4D by now.