I'm trying to use the fluid sim to create a vomit VFX shot for some live action footage I've got. But I'm struggling with getting it look the way I want. So far this is what I've got:

enter image description here

I'm relatively happy with the way it lands on the floor (except for the jittering), but I'm wanting to improve the way it falls. Currently it just flows too smoothly, where as I'd like it to be more like this:

enter image description here

So it has more of a 'spraying' and forceful quality to it, where the diameter starts narrow at the source (The mouth) and then it spreads out the further from the mouth it gets.

Any suggestions?

  • 1
    $\begingroup$ We should migrate the question again, I think: alcohol.stackexchange.com $\endgroup$
    – lemon
    Mar 19 '17 at 18:45
  • $\begingroup$ Sounds like a matter of tweaking some values like viscosity weight or speed. Otherwise you could try particles instead of fluids. $\endgroup$ Mar 20 '17 at 1:34
  • $\begingroup$ I think that you will need to use particles in Fluid mode, perhaps metaballs if you have the ram for it. This will give you the blobbly appearance then render with motion Blur (not sure if that will work with particles though). $\endgroup$
    – 3pointedit
    Mar 20 '17 at 6:34

You will need to use particles in Fluid mode, perhaps metaballs if you have the ram for it. This will give you the blobby appearance then render with motion Blur. You'll need to duplicate the particle settings and emitter for blur.

color render layer

vector layer with duplicate emitter

Use vector blur but you can only use Blender internal for that. Make a normal object particle duplicate of the metaball cascade, on a separate layer. Apply this vector blur to the metaball layer.

render layer 1

render layer 2

In the compositor use the 2nd render layer to drive the vector blur.

Send to compositor

Results with and with out blur, change vector object scale to suit blur.


You may have to adjust the particle life of the vector object so that you don't get blurring of the floor.

  • $\begingroup$ Nice workflow. However there's an easier way to get motionblur, provided you're rendering with Cycles: Just turn it on in the render panel. No need for renderlayers, and you avoid the artifacts too :) $\endgroup$ Apr 20 '17 at 1:42
  • $\begingroup$ Show off :P but yes Andrew is correct, fluid sim has motion blur as do particles in Cycles now. $\endgroup$
    – 3pointedit
    Apr 20 '17 at 2:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.