Misterious problem with inflow


As first trying the fluids in blender I was setting up an inflow but I must miss something from the proper workflow as the result is pretty weird.

As a test I have duplicated the basic cube and scaled it up a little bit. Enabled the large cube as a domain for fluid simulation and enabled the smaller cube as inflow. Everything was working great until I scaled the inflow down to be able to fit into a “tap” object and be proportionally correct with a “bath” object. It just stopped working. Instead of a continuos flow that would be expectable the fluid just drops into the bath from somewhere, instead of flowing. I was just wondering if it is possible to do a proportionally correct fluid simulation of a bath or maybe the fluids are not working above a certain scale? Or it is not possible to scale the inflow object?

The same thing happens when I scale the domain and the obstacle.

I should mention, that after each transformation I have deleted and re-applied the inflow on the objects and applied all transformations.

Any help and advise are very much appreciated…


i dont use fluid sims much, but try applying the scale of the inflow with ctrl-a.

good luck :slight_smile:

Here are a few ideas I would try.

My first thought would be to check the resolution of the domain. Try increasing it. And check to see if you’re viewing the preview resolution or the final resolution.

Check to see what the “scale” of the domain is. I would imagine a typical bath would be around 2m so I would set the domain scale to that, then set the “end time” of the simulation to however long the animation is. So if your animation is 250 frames long at 25fps, then the length of the animation is 10 seconds, so set the end time to 10 (just to keep everything in proportion).

Check to make sure you have set the inflow object to “inflow” and not “fluid”. I’ve done that a couple of times.

Fasty and youthofblender, many thanks for your suggestions.

I tried to apply the transformations. Actually it worked when I took off the simulation from all three object first, scaled them up and applied the transformation after this and re-enabled the fluids. I set the resolution to final which also helped a lot.

Once I thought I am there I have added some taps to the simulation but even if they have no any rule in the simulation, the system was messed up.

The inflow started dripping and I just cant understand why.

I have tried the correct size and time settings, and mysteriously the flow and even the dropping stopped after that and I can’t fix it even if I go back to the original settings.

It made me wonder if there is any cache conflict issues? I can’t see and empty cache button though…

I must have done something really bad. I am sure it is just a small thing as everything seems pretty straight forward but I just can’t figure out what happening.

Anyway many thanks for your suggestions. They all improved the simulation until I added the taps and scaled everything up again.
I will go back to a previous stage and try again.

Thanks again


perren, there are so many settings with fluids it will be exremely difficult for anyone to give you a specific answer on what will improve your fluid sim without actually seeing your blend file. Why haven’t bothered to attach your blend to your post, I take it that you want people to work as hard as possible in helping you find a solutiuon

Thank you for your reply Richard,

With the previous suggestions I have managed to progres a bit further, but there are still a few issues I just can’t figure out.

First of all this dropping issue is weird. I was trying to achieve a continuos flow. And the next thing is the size of the flow. I was expecting it to be the same “width” as the inflow object. Is it something to do with the real word size?

I have uploaded the .blend file to the following link:

Many thanks for all your helps, comments and suggestion…


Here you go, I think I’ve improved it somewhat.

I shrank the domain down to the smallest possible size to get more value for your resolution (I think that’s how it works anyway). Then I upped the resolution again to 300, and changed the domain-size down to 1m so there would be less of a chance for the water to break up, and turned up the flow a bit to 2.5 to try and get it to stay as a stream more.


Wow!! You did a much bigger improvement as thought is possible. Thank you very much for this. Last night I tried a couples of things and got a better result than before, but nothing close to this. Always when I tried the liquid was a bit bulky but I take it is something to do with the resolution. I could minimize the dropping with increasing the real world size and the initial velocity too. However never managed to get such a great result with only 1 meter real world size. It is a magic to me just now but I will try to reproduce and get a better understanding of it.

Many thanks for your help Fasty!!!