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Houdini Pyro simulation error

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Hi guys I have been running some Pyro simulations and I have been having some problems. it seems after a few hundred frames the sim dies

https://youtu.be/gSd0xT3JJQw- flipbook preview

This problem happened on houdini apprentice but has also happened on regular houdini 

Processor: Intel® Xeon® CPU E5-1650 v3 @ 3.50GHz (12 CPUs), ~3.5GHz
Memory: 32768MB RAM
Windows 7.
Card name: NVIDIA Quadro K2200
 
This was done on a university computer overnight. the sim should have only taken a few hours at most (500frames)
to cache I used a dopimportfield with I am fairly sure the default pyro settings and then a vomumecompress and then a filecache node which is what did the final caching 
 
I have had this problem before with high density smoke as well.
 
I cant post the hipfile as the uni comp shutdown without my knowledge after the sim finished and I forgot to save before I started it.
if you guys want later I can post a the hip file of my smoke sim that also did the same thing but I cant do that till tonight.
 
I was wondering if it was a ram issue or something or maybe a problem with how I cached it.

if you guys have any idea whats going on I would love the help.

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It is hard to say without looking at the HIP file. I wonder if some kind of overnight network maintenance might have interfered, however?

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The network maintenance might have crashed the houdini file but all the 500 frames were cached its just half way through they break.

I have had the same problem at home siming out smoke.
I will add the hip file for that one. 
The display sim and the low res sim seem to work fine but the upres sim breaks after 200ish frames and does the same thing as the video I linked above. it just hangs and then slowly disappears.

I am fairly sure its not the upres that's breaking because I tried to just run the lowres sim at 0.04 divisions and it had the same result.  

 

Smoke sim setup.hip

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Hi Prakash,

Your low res sim contains 2.35 million voxels at frame 200. Your upres sim division size is 60% smaller than your low res sim. The upres sim would have had an insane number of voxels. Low res should probably contain around a few hundred thousand voxels with an upres division of 50% the size of the upres, roughly. 

 

You are running out of ram. If you *really* want to run the sim at these resolutions you can safely uncheck Dop Network>Cache>Cache Simulation. The idea of this caching is for scrubbing/flipbooking. You are not previewing this stuff. You do not need to cache it to memory because you are writing it to disk. Uncheck this option on the low res Dop Network and the upres Dop Network. I would also suggest increasing the division size of your low res sim by a factor of 3 or 4.

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Ahk thanks I will give it a try.
So its that I have been caching all my sims while I write to disk which has been filling my ram causing it to break when its full.

Is that the general idea?

I will run a sim tonight and report back.

Thanks for the help 

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Ahk thanks I will give it a try.

So its that I have been caching all my sims while I write to disk which has been filling my ram causing it to break when its full.

Is that the general idea?

I will run a sim tonight and report back.

Thanks for the help 

The primary cause of running out of memory is the high voxel count on your low res sim. When you upres it, the voxel count shoots through the roof and you run out of ram. You most likely do not need that kind of resolution. If you uncheck the caching option and you run out of ram you must use a machine that has more ram or lower your voxel count. 

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i would also make sure you don't have any opencl dops activated.  when the gpu runs out of ram, it will introduce weirdness into your sim in a semi-failed state....

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it will introduce weirdness into your sim in a semi-failed state....

 

 

...and could fry a graphics card as one might discover the next morning!  :o

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...and could fry a graphics card as one might discover the next morning!  :o

 

Wow really. I have had problems with opencl in the past so I don't use it now.

 

I ran my smoke sim last night but it seems its a different problem then what happened with my fire sim.

I watched the ram usage for about 500 frames and it never went past 8 gigs (I have 24) but about 400 frames in the smoke comes to a stop and hangs which now I am thinking is a problem with my sim setup.

Everything looks fine with my lowres.

 

My goal is to have a smoke sim that runs for 1500 frames with the first 300 or so producing smoke and the last 1200 being the smoke flowing and dissipating (no extra smoke produced).

I thought it might be my upres that was breaking it. so I tried to cache the low res with a smaller division size and I still got the problem.  

 

I can see if I can post a video of the problem but my internet is really slow so might take a while.

 

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