Fluid velocity frame blending crashing

[PowerCreative]

Hello everyone!

I have a 400-frame fluid sim that consistently crashes about 30% in. I think I've pinpointed the cause of the crash - I'm retiming my 200f sim in the scene by changing the time bend mode to 'cache index' under 'Input', animating the index to scale time within a 400f sequence. If I have 'Frame Blend' to 'Interpolation', no crash but undesirable results - if I set it to 'velocity' (for a smooth interpolation between sim frames), it eventually jacks my memory up until crashing (several frames into the interpolation blending). I can't preview viewport sequence, render or export the mesh as alembic without it crashing. If I resume render after a crash, it renders a few frames, runs out of memory and crashes again. Frame blending with velocity is killing my machine.

At this point I can't render the mesh, I can't export the mesh... what can I do? Is this the kind of thing people use Krakatoa for, to retime? Would I then need to use Frost to mesh? I have no budget for additional tools, I would love to retime with Phoenix... How can I keep the memory from getting out of control until crash? Can I retime the sim data itself without using frame blending and messing with the input?

3ds Max 2017, Vray 3.4, Phoenix FD 3
Xeon E5-2650 2GHZ w/ 64 GB RAM
Titan X

Let me know what other information you need - Thank you for any guidance!

[Svetlin.Nikolov]

Hello,

Please don't use Velocity blending - change it back to Interpolation. We found and fixed a memory leak there and the fix will be in the nightlies when we make them open, hopefully in a couple of weeks.

About retiming, I didn't understand if you are simulating liquids or fire/smoke - if you are retiming liquids, only changing settings in the Input panel would be enough and you wouldn't need the Velocity interpolation anyway. If you are retiming fire/smoke, then please check the docs site for more info on that - https://docs.chaosgroup.com/display/...time-scale,etc.

Generally, the Velocity interpolation is slow and gives bad results anyway, so I'm thinking of removing it altogether.

Cheers!

[PowerCreative]

Got it! Changed it back and I'm not seeing the popping mesh that I saw before... I don't know what I did wrong before, it could be 1 of 50 things, so many variables - maybe it was a lower res sim. Lower res usually generates a less smooth and shaky surface. Anyway, I captured a viewport sequence with no crash. I expect render to be just fine now.

Thanks for the help! I'm always surprised how fast you guys reply to help via forum or email.

Edit:

Scene rendered no problem after ditching 'velocity' interpolation. No crashes, just glorious fluids!

[hammerbchen]

I have the same issue. Same scene happen only in my laptop, not the machine in the office (which is much powerful), so I thought it was a hardware problem. Tks for the reply.