FLIP Fluids Addon: A liquid fluid simulation tool for Blender



Thanks that was very helpful, i had a ton of Motion Blur in my render, I’ll try turning that off, using 50% less particles, and rendering from the command line, just one more question, how about depth of field, does it matter that much in render time?

(RLGUY) #606

No problem! I haven’t experienced any problems with performance related to depth of field. It doesn’t sound like it impacts performace according to this post: https://blender.stackexchange.com/questions/57355/does-cycles-dof-use-more-resources

(lumpyoatmeal) #607

ARC9, for the motion blur, the one that I’ve found makes it very slow is the one in the FLIP Fluid Surface panel, whereas the one in the FLIP Fluid Display Settings seems to be ok.


I didn’t want to risk waiting for a long render again so i turned off everything that resembles motion blur lol, I’ll keep that mind for next time though, thanks.

(RevDr) #609

The automatic motion blur option in DaVinci Resolve is not available on the free version. I have tried using the optical flow settings inside the Fusion section of Resolve, but that didn’t seem to give me great results for Flip Fluids - although that was probably how I using it.

What worked for me in my Baptism Project was to render a Vector pass out of Blender and use that in the Vector Motion Blur node in Fusion. I used the free stand alone version, although I guess you could use the one within free DaVinci Resolve too (I prefer the work flow of a separate Fusion).


Thanks, I’ve used fusion before and I couldn’t for the life of me get my head around its workflow, i remember i used Adobe After Effects to add motion blur to a small fracture sequence I’ve made a while ago and it seemed to be way easier especially for beginners like me, do you think that would work just as well?

(RevDr) #611

I’ve not used AE but as I understand it AE works out the MB automatically with some clever image analysis. This is a similar idea to the MB in DaVinci Resolve (paid version).

Using a vector pass from Blender is a little different because.
a. It gives you the actual motion vectors from within Blender, so nothing is estimated
b. FlipFluids does not give MB vectors for particles, just the surfaces. You can sometimes spot that in my Baptism Project.

(RLGUY) #612

Hey everyone! We have a new video online: 10 Tips to Improve Your FLIP Fluids Workflow in Blender:

And if you prefer reading to watching, you can also find these tips in a written article on the Blender Market blog: https://blendermarket.com/posts/flip-fluids-10-tips-to-improve-your-blender-workflow

(lumpyoatmeal) #613

Operating System: Windows 10
Blender version: 2.79b
Addon version: Experimental 01-FEB-2019
CPU Model: AMD 2950X
GPU Model: GTX 1070

After baking 14 frames, when I try and render the last frame blender quits with “Error: EXCEPTION_ACCESS_VIOLATION”. This happens with either the GPU or CPU selected for rendering. Tile size for CPU rendering is 32.

It succeeds when I run it from the command line with

“c:\program files\blender foundation\blender\blender.exe” --background untitled.blend --render-frame 14

If I replace the Flip Fluids add-on with the 24 DEC 2018 experimental version it runs fine without having to resort to the command line.

(RLGUY) #614

Thanks for the report! Do you have a .blend file that I could test and try to reproduce this error?

Also wondering: was the simulation re-baked with the 24 DEC 2018 version, or was it still rendering the same cache as the 01-FEB-2019 version. If it is the same cache, this might be able to narrow down the problem to any changes in the rendering code between versions.

(lumpyoatmeal) #615

After a little experiment I think it’s some random bug in blender. It had been working earlier yesterday and Monday with no problem. I built my new system this last weekend and as a result reinstalled windows and everything else. I’m pretty aggressive at making lots of changes to the startup file and I’d forgotten to add the environment lighting that uses an hdr. It seems to have started after I added that. So then I took that out and it started working again. Then I put it back in and it’s still working.

(lumpyoatmeal) #616

Implied but not stated in my previous post is that I didn’t use the previous blender startup file from my prior system and remade it from my notes.

(lumpyoatmeal) #617

I have the task manager set to show me the cpu usage graphs for all threads/logical processors. When I’m baking a flip fluids simulation all 32 of mine are busy.

There’s a tweaker thing that came with my Asus motherboard that figures out how much it can crank things up for the cpu (cooling is a major factor as I understand it) and mine now has a base speed of 4.03 GHz.

(RLGUY) #618

Thanks for letting me know! That’s some good info. During the beta, simulations run on threadrippers had terrible performance. Since the release we have been focusing on optimizations that improve multithreaded performance, so this has likely resulted in better use of threads on your threadripper.

(Razorblade) #619

How does flipfluids compare to mantaflow ?.


My half guess is that Mantaflow is more empty than FlipFluids
That and Mantaflow is taking much longer to develop.

(Wig42) #621

Flip Fluids is faster than Realflow and has the convenience of being inside Blender. It is also very similar to Blender’s native fluid sim so not a very steep learning curve. Flip fluids is awesome. Realflow is much more powerful and customisable, has 3 different fluid types the most importamt being the Hybrido which can interact with rigid and soft bodies (If Flip fluids ever gets that feature then Realflow can be put to bed haha). In short Flip Fluids is just a very small part of realflow, but what it does it does really well and it does really fast.

(RaphaelBarros) #622

Is it really faster than Realflow? I’ve never used it, but I had the feeling Realflow was faster, especially being able to generate the particle simulation previously and meshing only after you’re happy with the overall flow, which is specially useful when you’re not after the most realistic stuff, such as particles following a path.

I’m really a beginner where it comes to simulation, so I may be completely wrong.

(Wig42) #623

In realflow you simulate the particles first, then you mesh them, then once you have your mesh you simulate your splash particles and foam particles and spray particles. So you can end up simulating 4 or 5 times. With Flip Fluids it is all done together. Don’t get me wrong Realflow is better but it takes a lot longer and as it goes Flip Fluids does a brilliant job. As I said before the only thing letting Flip Fluids down is no rigid body interaction, which Realflow does have. Oh and wetmap generation is so easy with Realflow too. Add to the fact that Realflow has a great Ridgid body simulater in Caronte and a cloth sim as well. Flip Fluids is never gonna compare to Realflow, but also as I said earlier what it dees do it does nearly as well as Realflow. Abosulely brillian Blender addon and very easy to use too.

(RaphaelBarros) #624

Thanks for clarifying. I’ll keep my eye on FLIP Fluids. I’m thinking about getting Houdini Indie as well.