Creating renderings of the simulated fluids (possible via .uni files?)

[Johannes Unterguggenberger]

Can the exported .uni files be imported into blender in order to render the fluid?

If yes, how can it be done? (Maybe via texture --> voxel data --> and choosing the right file format?)

The reason why I'm asking is because I want to establish a workflow for me including the rendering of the fluid in a similar way as it has been done for the "Narrow Band FLIP for Liquid Simulations" technique. How were the beautiful renderings in the video [1] created (combination of the volume and the particles)?

I've been able to import the fluid surface as mesh into blender (using all those .bobj.gz files) and render those, but for smoke, like e.g. in "Wavelet Turbulence for Fluid Simulation" [2], a different rendering technique must have been used. It would help me a lot if I knew how the renderings have been created.

[1] https://wwwcg.in.tum.de/research/research/publications/2016/narrow-band-flip-for-liquid-simulations.html

[2] https://youtu.be/xMn9MrSvN-A

[Nils Thuerey]

Hi Johannes, 

the NB-FLIP renderings were using a few custom scripts to export the FLIP particles. The liquid surface is a regular bobj sequence, which is easy to render (as you mentioned). For the particles, Florian instanced small tets that were exported as a second mesh from mantaflow, but that export was only a temporary solution for our paper. Sebastian (sebbas, https://wiki.blender.org/index.php/User:Sebbas/GSoC_2017) is currently working on a more seamless integration of the particles into Blender, a first version of which you could check out in his GSoC branch.

For rendering uni file sequences we don't have any standard workflow or example scenes at the moment. It should be relatively easy to patch the python scripts in blender to load the uni files instead of simulating them, though. We'll definitely work on that at some point. Our goal is to support blender internal as well as external mantaflow simulations. (Btw., currently, the easiest way to render smoke volumes in mantaflow is to export .vol files for mitsuba.)

Cheers, Nils 

[Johannes Unterguggenberger]

Hi Nils,

thanks for your reply and all the info!

Didn't know about the feature to export .vol files. That works great and I was able to render them with mitsuba renderer. Thank you!