I have my fluid simulation beneath a floor plane, and I only want the splashes that rise above the plane to be visible in the final render. I've been trying to find a way to make the pool of fluid below the plane invisible, but applying a boolean to the domain didn't work. I don't think an outflow object would work either, as I do need the fluid to be there in order for it to splash.

Is there any method out there for doing this?

  • $\begingroup$ If I understood Boolean should work, tested here blender.stackexchange.com/questions/176612/… probably you should post your simplified blend via blend-exchange.giantcowfilms.com so we can check $\endgroup$ – vklidu Jun 18 '20 at 6:15
  • $\begingroup$ Thanks for confirming that is the right method. I'm going to take a look at that thread and see if I can figure out what step I missed. I'll post back $\endgroup$ – Tyrannosaur Jun 19 '20 at 0:10
  • $\begingroup$ So it does in fact work using a boolean, but not if the fluid mesh has been converted to particles. I thought this was the accepted practice for fluid sims but I'm assuming there's also a way to texture your fluid without going the particle route. I'm going to look into it $\endgroup$ – Tyrannosaur Jun 19 '20 at 0:51
  • $\begingroup$ What? I don't understand your comment and probably for that I don't see a relationship to your original question. $\endgroup$ – vklidu Jun 20 '20 at 5:57
  • $\begingroup$ I meant when you go into the particle settings for the fluid sim and by default it is set to "Halo" which as I understood it would not render. So I set this to "collection", where I have several UV spheres with the material I want. Using this setting,t eh boolean did not seem to work. $\endgroup$ – Tyrannosaur Jun 21 '20 at 6:08

In case of Particles System type Fluid, there is not a direct way to hide part of particles. You would have to convert sim to mesh.

In this example I used Metaball as particle (because Icosphere object keeps particle system after export).

  • export into Alembic format
  • import back and use Boolean Modifier

enter image description here enter image description here


OK I got it, you mean particles generated by Fluid Simulation (Mantaflow) - Liquid and Spray.

enter image description here

Yes, particles are not affected by Boolean Modifier. enter image description here

So there does not exist a way to hide a part of released particles. So only way I know is to use Mball as particle and export-import it as Alembic and use Boolean. enter image description here

Note: In theory - to exclude some particles from render you can influent particles size by Texture, so classic particle system can do this, but fluid sim particles doesnt have such feature.


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