Hi All,

I have been struggling with this for months now. It seems like no matter what Houdini has a bottom resolution for pyro of 0.1. If I try to export the result of my simulation to .bgeo.sc files I get a few frames, maybe 40 or so, then Houdini crashes.

At first I thought, Ok, maybe it's my computer somehow or I don't have enough memory. So I bought a completely new computer with more memory, 48Gb and Houdini still crashes.

I can't get any professional resolution out of Houdini pyro.

What causes this crashing?

Is there any work around?

I've run Pyro sims down to 0.02 and even 0.015 on a 64gig box my guess is it has to do with the scene scale you're working at

I can't find any crash log, but the event viewer reports this as a crash in the VEX lib. With my div size of 0.1 I am guessing I am generating around 180 million voxels, which does fit within my physical memory of 48Gb.

The div size doesn't matter at all, it's the number of voxels. I've run 0.0007 size simulations before without any trouble. They just weren't very big. Try limiting the dimensions of your container better. If you a resize based on a fluid source, if the source suddenly does not exist, if you don't set up the resize correctly, your simulation may suddenly resize to fit a point at the origin, which could potentially make your grid thousands of times larger. To ensure this does not happen, use a switch to a null for the source bounds whenever it doesn't exist.

Great tip. Along those lines Max Axis can be a quicker way to set grid resolution independent of scene scale. A shot in the dark, but there's also the possibility you have a bad memory DIMM? I'm not a hardware guy but I've heard of situations where bad memory chips only manifested when all the memory address space is in use, such as when you run large scale sims

Fwiw just processed 50 frames of 280 million voxels in ~7GB of Ram.

The computer is new and the memory is new so I am hoping it is not a hardware issue. And because I get a similar crash on my older machine I don't think it is hardware related, but actually Houdini bug related.

Does anyone know how to calculate expected voxel count from the bounding box and the divsize?
It would be a nice feature to have. Also expected memory usage for your current settings would be nice to have as well.

I do realize that after I have computed a volume I can middle click on it and see the resulting voxel count, but I have to wait hours to get to the middle of my sim to inspect such a value. An estimation calculator would be great.

I am using divsize instead of max division because Jeff Wagner mentioned it is a better choice when you have a changing box size. In the video he stated, divsize is always the same size while Max Divisions can change resolution based upon the changing size of the domain.

Hi Enivob,
Have you found a workaround to the crashing issue you had?
I faced similar issue recently. Tried various Operating systems and Nvidia driver versions, which did not help.
The actual issue was with Bios Cpu Overclock settings, Changing it to auto mode seem to have solved the issue. Hyperthreading is enabled and I am able to run Pyro without system freezing.

Hope this helps.

Thanks to Mehdi Daghfous and Saber Jlassi for pointing me to the right direction.
Regards
Thomas