hello,

I got a FLIP sim and want to write it out to disk.
What is the best method?
I don't want the blue cache line, because for the moment I got little ram (4GB)..

thanks,

bern

Actually I think you have only 3 method !

1. Use Explicit Cache for writing your simulation as *.sim files
2. Use ROP Output Driver node inside AutoDopNetwork for writing them as *.sim files
3. Use ROP Output Driver in the Geometry Network for writing them as bgeo files (if you don't wanna continue your simulation later )

I suggest you to save your simulation with last method , it's so handy and you can compress your files with new Houdini 14 zipping system (*.bgeo.sc ) , it's so faster and better than old one. (*.bgeo.gz)

Also you can delete some unwanted attributes before writing them to the disk to achieve less size.

About your very low RAM you can decrease Cache Memory (MB) parameter in the AutoDopNetwork node , even you can set it to zero (of course if you don't have any RBD dynamics ! ).

Hi there

I found this thread as I am having some issues caching out .sim files and .bgeo.gz files.

I've tried the built in .sim rendering method which can be found on the AutoDopNetwork with the “Save Checkpoints”.
This worked for a couple of frames when just letting it play, until my Houdini crashed.
Then after that it didn't create .sim files anymore when playing.

Also, Windows tells me I'm out of RAM when I render out the particles to .bgeo.gz and hitting 660.000 particles at 32MB/frame.
I have 16GB of RAM and I remember sim'ing to about 1.000.000 particles before on the same machine.
The memory limit on the AutoDopNetwork is set to 5000 until it writes to disk. So I'm not sure what is going on in my situation.
The problem is that I can't sim my entire effect because of the memory issue. So I would want to chache the .sim files so I can start over from where it stops, but writing the .sim files don't seem to work either.

Any clarification is more than welcome.

Thanks in advance!

@Eckxter
Can you post your file?

Oh right, my apologies.

The only thing that should be missing is a zombie head model.
You don't really need this piece as it is just a collision object, but the fluid doesn't hit it in this setup. So it can be ignored/removed.

Actually zombie geometry needed since you are sourcing from it. If it's possible then upload zipped file.
BTW why did you set viscosity on so many places?

Oh righ… I'm an idiot.
I forgot that small patch comes from the head as well.
Model is in attachment.

And the reason for all the viscosity is because I want to put some noise controlled viscosity in the fluid, but it didn't seem to work the way I normally do it.
So I tried to put it wherever I could to see which one worked.
I've done viscosity in fluid sims with Fluid from Object, where I set up a custom viscosity attribute in SOP level and use those values in DOPs.
But this doesn't seem to work (or I'm just doing it wrong) with Emit Particle Fluid as the custom viscosity attribute gets removed or overwritten by the Fluid Source node in SOPs.
And as far as I've been able to figure out, I need that node for the Fluid Particle Emitter to work.
So what I want to accomplish in this effect is just that every emitted particle has a different viscosity value.

As that is a different topic, you don't need to help me out on that here.
But if you want, feel free to point me in the right direction

Thanks!

I've put 16GB extra RAM in my machine and cached out a bigger simulation, with .sim files and everything and no errors occurred.
So I guess it just came down to having not enough memory.

I had tested the .sim chaching in a different file after expanding my RAM and it worked fine.
I've been trying it on the file in which I had the issue initially and it still remains.
It just doesn't create .sim files when I let it play.
I've set the DOP network to “Allow chaching to disk” and check on “Save checkpoints” with a correct directory, but nothing is being written.

Any help would be much appreciated!

If you're going to check out the file, you're going to need the zombie head from one of my previous replies.

OK, now I've tried some things out and it started writing the .sim files after I changed the destination folder from SIM_CACHE to SIM.
No idea why that would matter.

Then I've also tried to have it write every 2 frames, but it didn't.
Neither every 3 frames.
Only when I have it on every frame, it writes out the .sim files.
Is this a bug or am I doing something wrong?


Thanks in Advance!

May be you got your answer here:
https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=37850&start=0&postdays=0&postorder=asc&highlight= [sidefx.com]