An Introduction to Fluid Simulations in Blender

on Aug 7th 2009 with 41 comments
Tutorial Details
  • Software: Blender
  • Difficulty: Beginner
  • Estimated Completion Time: 1 Hour

Learning to simulate realistic fluids in any 3d app is always a challenge, but Blender’s sophisticated solver allows for some very rewarding results.

In this introduction to Blender fluid simulations, you will learn the basics of how to set up a fluid simulation in Blender with an obstacle, and a few fluid set ups to give you an idea of some of the other things that you can do with Blender fluids.

Final Effect Preview

Tutorial

Note: click the ‘Monitor’ icon to view tutorial in full-screen HD.

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By

Rollover to read this author's bio or click through to see a full list of posts by this author.

My name is Greg Dunn, and I'm one of those unusual hybrid programmer/graphics guys. As far as graphics go, coming from a programming/technical background, I usually focus on how programs work and can pull out details and features that people often overlook. When I have my choice, I'm usually drawn to more specialzed stuff like particles, fluids and motion graphics. I'm currently mixing my two main interests in my first iPhone game, using Cinema 4D for the graphics and doing the programming myself. I work primarily with Cinema 4D, Blender, After Effects and RealFlow. You can find my website at http://www.unseenthings.net/.  

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  • Hiruy

    Green liquid! That will come in handy ;>

  • Bryan

    Nice tutorial :)

    Now if only 3ds max had an internal fluid simulator… :(

    • Pawel

      Time to switch to Blender, then. ;)

      • http://thespstudios.webs.com SP Studios 3D

        Amen Brother! :D

  • Just me!

    Great tutorial!

    Except for the part when you use the ACTION EDITOR to scrub! The TIMELINE exists for some reason, don’t you think!

    Anyway, keep going!

  • http://blenderguru.com Andrew Price

    Could have put a little more effort into the final preview don’t ya think?
    At least change the default blue background, pull the camera out slightly and make the liquid anything BUT green slime?

    I’m sure it’s a good tutorial, but the final preview repulses viewers.

    • http://www.unseenthings.net Greg Dunn
      Author

      Good points — I know, the green slime is pretty hideous, right? I really did want to make the final preview look different, but I had to cut out several minutes to fit within the allotted timeframe, and I could’ve done something nice and fancy for the preview without letting people see how I did it, but it always frustrates me when I see one thing in the preview but it’s not what I end up creating. I’m hoping (if there’s demand) that I can do a more in depth follow up tutorial and we’ll definitely end up with a much nicer looking end result. There’s a lot more that you can do with blender fluids, I just didn’t have time to cover it. Yes, I could’ve taken 30 seconds to make those quick changes, but this tutorial was primarily about how to use the fluid simulation chunk of blender and not teach people how to create a specific look and feel/effect of the fluid. I’m also hoping that people will use this tutorial as a starting point and add their own textures/scenes and expand on the tutorial.

      • accessoire

        I’m going to try this out this weekend. I’m glad this tutorial was posted, because I am looking at the physics stuff a lot lately. Is there a flickr group or something like that for cgtuts, where we can share our work with the community? Ok, I know flickr is a stupid idea for motion graphics ;)!

  • Willem

    I think it’s good to see someone telling some stuff on the subject.

    However, i also think your example looks like absolute shit, and doesn’t show what the solver is really capable of.

    So kudos, and also no kudos. With a bit more homework this could be nicer.

    • fogfrogblog

      Why don’t you show us some of your tuts?

  • Felix

    good tut, man. Thanks.

  • IHazBlender

    Just to add some tips for final rendering.

    1.You may very well have to wait 10+ hours, I have known people to wait 60+ hours just to get a high quality fluid simulation. Don’t settle for under 3 hours.

    2. Get your res as high as you can without crashing blender. 100-200 res looks like crap. People have fluid sims that are 1024 res. One-thousand-twenty-four, yeah, that’s intense. Here is the link /watch?v=JUyv0INBmAU. There are toooo many youtube videos of 100 res fluid sims, a lot of them have 1 star ratings.

    3. Fluid simulations are not for the impatient. Quality is a necessity. No one likes weird blob things that is supposed to be water.

    4. When adding transparency, and you are going for realism, under the IOR use water’s actual IOR. Objects in the real world, like glass, and water, have an IOR. Google the IOR of water and use it in your transparency settings. IOR is index of refraction.

    5. If you really want to add that extra kick. You could try yafaray, and external raytracing rendering engine. It is very good for glass/water/glossy materials.

    6. Some examples of good fluid simulations in blender on youtube.
    /watch?v=k8eV9XMr7Gc
    /watch?v=JUyv0INBmAU
    /watch?v=-AiLyQWXjIg

    • Dark0Lord7

      How can people bake with 1024 res???
      that’s impossible. do they use 64-bit operational systems?

  • Kris

    This is awesome! Thank you very much for taking the time to create this tut. I for one loved the green slime. I immediatley thought of a video game environment that I’d expect to see something like this in.

    Do you have any examples available of clean clear water though?

    Thanks again!

  • Timo

    could we have a download link for the tutorial?

  • Dj

    I’ve watched a lot of these tuts since the inception of this site and must say that your style of teaching is probably one of the best “tuts” has. I watch most all of them (don’t fully understand many but enjoy the concepts) but this has been the most useful. Thanks.

    Would definitely like to see more Blender related tuts! And don’t be afraid to get what you might call “basic” – all god’s chillin’ needs to start somewhere! Jeffery, I’m sure got a lot of smart but inexperienced people to take the first step with his jQuery for absolute beginners series.

  • Willem

    Greg,

    What would be interesting is to show how to get the water looking realistic.
    The main problem i find with the Blender solver is that the drops/particles don’t relate to real-world physics, in the tests i did anyway.
    So you get these really big drops and splashes and it looks like anything but real water.
    However, i’m sure that with the right kind of tweaking the solver should be able to give acceptable results. But there’s a lot of parameters to learn here, and usually a very long time needed for calculations which don’t actually make it fun doing a lot of testing.

    • http://www.evanschaible.com Evan Schaible

      The algorithm that the Blender solver is based on is actually capable of true to life results, you just have to know what you are doing. Blenders solver in my opinion is better than RealFlow. I have used RealFlow for long time, and when I learned how to use Blender, I actually replaced it RF4 with it.

      • Willem

        Evan,

        You’re right. But as of yet I haven’t been able to get good results for anything bigger than a glass of water though, because at bigger volumes, the drops just are too big and i’m curious to see how to set the parameters for larger objects of fluid.

    • IHazBlender

      Here is your giant glass of water.

      this is a youtube link to a tsunami someone made in blender /watch?v=ocnLSuuljPo

      There are even larger scale simulations if that one is too small for you.

  • http://www.alejandrososa.com Alejandro Sosa

    nice tutorial man!

  • Catho

    Vid stops @ 2:41

    • Catho

      I mean the Tutorial Video

      Sorry :)

      • http://kaleb-3d.com Kaleb Aylsworth

        I checked it out, but it plays past that point just fine for me. Anyone else having trouble with this vid quitting?

  • fxgogo

    Great tut, got me going in a morning. Gotta make a T2 style promo, so this will come in handy thanks.

  • Garrick

    Great tutorial!

    I am new to blender, an am look to import the object sequence to Modo.
    What file format can this be exported in?

    • mel

      have you tried collada format?

    • http://www.evanschaible.com Evan Schaible

      collada

  • Ajith

    Hey greg,

    nice job making fluid simulations seem like a piece of cake :). There are some basics needed to be cleared first as the fluid simulation method in blender is not very obvious, and you pointed them out just fine. I had all my doubts cleared today on how to get started atleast. The way your final output looks doesnt really matter whether it is slimy green or bloody red as long as i can UNDERSTAND what you did to make fluid to simulate that way. I think its a perfect beginning tutorial for any one whos new to blender fluids. Nice clear HD video that too!!! :) :) :). Great job sir!!Would certainly love to see more …..

  • Pedro Bastos

    That’s a very good introduction. Make more! :)

  • Arn Sweatman

    GREAT tute, Greg. The audio and video quality were excellent as was the content. Please make another.

    Who gives a fluck if the fluid is green?

  • renato

    very understandable and very useful
    perfect choice of presentation

    are we gonna see somenthing about the OUTFLOW?

    thanks renato

  • renric

    Thanks a lot for this great tutorial. I learnt a lot about the basics of fluids sim in Blender.

    One question: there is any way to export the fluids sim to Cinema 4D?

    Thanks again,

    E

  • Seba

    Thx for the tutorial, was very useful :)

  • The Abu

    Thank you very much for this tutorial, I really enjoyed it. I’m more and more considering to learn blender and you gave me one more reason :)

    Jean-Luc

  • Ben Anderson

    Thank you for this fantastic tutorial, you spoke very clearly, covered the fluid system very well and you talked about the technical side of Blender and why it does what it does which I really enjoyed learning about. Please really consider making another Blender tutorial soon.

  • http://poliman.pl/ Strony Internetowe Kraków

    Hello, thx for tutorial, final preview … not perfect. but a lot to get from tutorial. thx

  • Francis

    Thx for tut! It is really good one. I think that it is enough to start playing with fluids on your own. Gives base to create more complex simulation and effects. Of course I used red color for fluid and simulated blood stream from shoot wound… But that’s just me… ;)

  • timmylynn

    that was very good tutorial. i’m picking up pieces and getting better. i learned a lot from this one. what disappoints me is some of the people complaining about crazy things like the colour of your background or fluid. that is ridiculous. thanks for the free info. complainers are just ‘capitalists’ and it disappoints me even more when their not even ‘american’s’ i thought american’s where the great ‘capitalists’!!! great job and thanks again for the help.

  • Ayman

    Where is the Bake button in 2.5?

  • Arn Sweatman

    Quickly covers the rudiments of Blender’s fluid simulation. 5/5

    who cares about the color?!? it’s a FLUID tutorial!!!