I've set up a simple scene with an inflow source and an outflow object that the simulated mesh hits perfectly.
Here's a pic of my domain settings:
Domain settings

As you can see I'm using Fluid Particles setting but without any particle system outside this option. It gives me a more interesting and realistic result. The problem is this, however the Fluid Particle option gives me the desirable result in mesh definition, it also creates the secondary particle-mesh that doesn't get removed when it hits my outflow mesh and just goes through.
Here's the illustration:
enter image description here
I even created an additional plane, you can see the black outline (it's solid, just set to wireframe render) and made it outflow, thinking that maybe my main mesh has some problems... didn't help.
What do you think is that a bug or I just missed something?

  • $\begingroup$ Are you sure this doesnt work? I tried recreating your problem and it seems to work with particles as long as the outflow initialization is set to "both" (shell+volume). The default setting is volume, and the plane will never work as an outflow because it has no volume, its 2D. Can you paste the blend so we can test with your setup? (preferably with included fluid cache so we dont need to recalculate) $\endgroup$
    – AdamTM
    Commented Jul 25, 2017 at 13:09
  • $\begingroup$ Nevermind, i should have let the thing bake entirely, it misses the particles. $\endgroup$
    – AdamTM
    Commented Jul 25, 2017 at 13:21
  • $\begingroup$ Does this still happen when viewing at full resolution? It could be an artefact of low resolution preview. $\endgroup$
    – SchoolBoy
    Commented Jul 25, 2017 at 15:17

2 Answers 2


It does seem to be a bug and should be reported. Though it seems that there is currently no one maintaining the elbeem fluid sim code.

A possible work around would be to use a boolean modifier.


Note that you'll need to bake first. I left the boolean modifier off (eye icon not checked) to illustrate that the boolean modifier removes the resultant fluid mesh, so you may need to tweak the boolean object to catch any particles/mesh that happen to move above the boolean object later in the animation.

Also, using a boolean modifier with a fluid sim mesh will likely really drag down the UI responsiveness.

  • $\begingroup$ Unfortunately that workaround doesn't work, or at least, doesn't provide a solution to the problem. Yes, the simulated mesh gets removed while it's in the cube but, when the fluid is past that cube, it reappears. In your example the boolean cube and the domain are at the same floor level so you don't realize that it just masks the fluid (you can raise the bottom face of the cube and see for yourself). Anyway, I appreciate the effort, it's a really non-trivial problem. $\endgroup$ Commented Jun 9, 2017 at 4:05

It's a confirmed bug. Here's a link to the Blender's bug tracker.
There's also a patch. According to the patch commit page it's in master, so it should be fixed for the 2.79 release.


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