Fluid simulation: Examples show much less RAM consumed?

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Hi!

I recently bought a new PC with some slightly advanced simulations in mind. But when trying it out, I was surprised how some people were able to squeeze Resolution divisions up to 1024 samples with only 32Gb. And when I try to replicate it, not even 192Gb of my own RAM is not enough.

I was looking for a solution/explanation on why is that this afternoon and haven’t found anything useful to my case.

So, maybe some of You might save me some trouble and point out the issue/setting I need to be more aware of.

I believe all presets are stock in the file below, besides the resolution. Foam, spray and bubble particles are on. The pic is showing 128 resolution.

test_water_anim128.blend (1.2 MB)

image
image1920×1080 605 KB

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in that link the video is using the flip add-on not blender’s vanilla mentaflow

Screenshot from 2024-01-20 15-43-43
Screenshot from 2024-01-20 15-43-431952×1185 337 KB

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I noticed. I just wasn’t able to find much useful information or demonstration on basic Mantaflow. I’d like to start with understanding basics before buying addons I might even need in the end.

Plus I figured some simulation addon can’t be technically several times less demanding than original. Or can be?

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ok. just wanted to draw your attention you were not doing apple to apple comparison.
how demanding are other add-ons i’m not sure i never used any add-on for this.
did you say you exceeded 192GB with 128 or 1024?

cause it sucks and not a lot of people/none are using it for serious projects

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did you say you exceeded 192GB with 128 or 1024?

1024

cause it sucks and not a lot of people/none are using it for serious projects

Ok, I know Blender is still far from perfect, especially in comparison with other professional SW. I just cought me by surprise, that memory consumption.

I’ll check what addons people use the most. I just usually end up creating my own solution, as many addons don’t do everything I need. Maybe this will be different.

Thanks for the reply.

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just a heads up here is your scene with 1024 right after it’s done with the first frame:

Screenshot from 2024-01-20 16-28-25
Screenshot from 2024-01-20 16-28-252071×213 25.2 KB

another issue with blender mantaflow is the speed of calculation. im surprised that when i took the screenshot it’s showing 100% cpu.
usually it doesn’t scale well with number of cores
so even if you manage to get enough ram don’t forget to leave instructions to your grand kids to close blender when the simulation is done :rofl:

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@MoravianLion in case you didnt know - Mantaflow which is responsible for fluid simulation in Blender is basically abandonware. Last commit on their github repo is 2 years old and no one is working on it Blender-side.

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Yes, I just read about it on Flip fluid’s site, explaining state of things.

Thank you though for bringing this up anyway.

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Made in Blender. 512 Resolution Flip Fluids, 256 Samples in Cycles. 32 hour Bake, 45 Hour Render

I don’t know if I need that much RAM.
I think 1024 samples are too high.

Among the sample images I saw on sns, I saw the comparative images (quality) of Flip Fluids / mantaflow, but I didn’t see anything about the same issues mentioned.

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I don’t know if I need that much RAM.
I think 1024 samples are too high.

You need it, if you want to do scenes larger than your usual beach cut out.

Currently trying out Flip fluids demo and it seems to be consuming approximately half of what Mantaflow does.

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the scene @MoravianLion shared needed in the 40’s GB at 512 and baking was moving quite a bit
at 1024 more than 200GB and only the first frame cache file was written in like more than 12 hours on a thread-ripper 32cores, was curious and left it baking when went out but had to stop it when back home i could wait.

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